diff --git a/doc/connections/AI-CONNECTIONS.md b/doc/connections/AI-CONNECTIONS.md
index ac1ebdc2a9f..2ea4f268145 100644
--- a/doc/connections/AI-CONNECTIONS.md
+++ b/doc/connections/AI-CONNECTIONS.md
@@ -42,7 +42,9 @@ mode's form is shown below. Advanced opens the existing compatible-connection
 picker and provider setup. Execution environment selection lives in Configure.
 
 Back from subscription sign-in cancels that attempt and pending prompt or status
-reads. A session returned after Back is released instead of reopening sign-in.
+reads. A session returned after Back is released instead of reopening sign-in. If an
+aborted read hides the session ID, a separate owner lookup releases the attempt
+before a replacement can start.
 Selecting a subscription again starts a fresh attempt. Reloading the page can
 still resume a sign-in that was not cancelled.
 
diff --git a/ui/src/api/agents.ts b/ui/src/api/agents.ts
index 0de5f60a0d5..f192d65bc4c 100644
--- a/ui/src/api/agents.ts
+++ b/ui/src/api/agents.ts
@@ -346,7 +346,7 @@ export const agentsApi = {
   // Reads the caller's active login session for one company and adapter, with
   // no session id, so the browser rediscovers its own session after a reload
   // with no local state. A 404 means no active session for the caller.
-  getActiveAdapterAuthLoginSession: (companyId: string, type: string, options?: { signal?: AbortSignal }) =>
+  getActiveAdapterAuthLoginSession: (companyId: string, type: string, options?: { signal?: AbortSignal; fresh?: boolean }) =>
     api.get<AdapterAuthSessionOwnerResponse>(
       `/companies/${encodeURIComponent(companyId)}/adapters/${encodeURIComponent(type)}/login-sessions/active`,
       { cache: "no-store", ...options },
@@ -386,7 +386,7 @@ export const agentsApi = {
   // Reads the caller's active Claude setup-token login session, with no
   // session id, so the browser rediscovers its own session after a reload with
   // no local state. A 404 means no active session for the caller.
-  getActiveClaudeSetupTokenLoginSession: (companyId: string, options?: { signal?: AbortSignal }) =>
+  getActiveClaudeSetupTokenLoginSession: (companyId: string, options?: { signal?: AbortSignal; fresh?: boolean }) =>
     api.get<ClaudeSetupTokenSessionOwnerResponse>(
       `/companies/${encodeURIComponent(companyId)}/setup-token-login-sessions/active`,
       { cache: "no-store", ...options },
diff --git a/ui/src/components/OnboardingWizard.test.tsx b/ui/src/components/OnboardingWizard.test.tsx
index 9dc2e1d9648..a8cd96d090f 100644
--- a/ui/src/components/OnboardingWizard.test.tsx
+++ b/ui/src/components/OnboardingWizard.test.tsx
@@ -4014,6 +4014,68 @@ describe("OnboardingWizard restore-gate (stale localStorage across accounts)", (
       } finally { await act(async () => root.unmount()); }
     });
 
+    it.each([
+      ["claude_local", false], ["codex_local", false], ["claude_local", true], ["codex_local", true],
+    ] as const)("discovers and releases %s after its resume read rejects on abort (panel mounted: %s)", async (adapterType, panelMounted) => {
+      const claude = adapterType === "claude_local";
+      const activeApi = claude ? mockAgentsApi.getActiveClaudeSetupTokenLoginSession : mockAgentsApi.getActiveAdapterAuthLoginSession;
+      const cancelApi = claude ? mockAgentsApi.cancelClaudeSetupTokenLogin : mockAgentsApi.cancelAdapterAuthLogin;
+      const startApi = claude ? mockAgentsApi.startClaudeSetupTokenLogin : mockAgentsApi.startAdapterAuthLogin;
+      const session = { sessionId: "abandoned-session", environmentId: "env-sandbox-1", status: "waiting_for_user", expiresAt: null,
+        panelMode: claude ? "submitted_browser_code" : "displayed_code",
+        aiConnection: { provider: claude ? "anthropic" : "openai", method: "subscription", ownership: "personal", agentIds: [], allAgents: true } };
+      let serverActive = true;
+      let aborts = 0;
+      let finishDiscovery!: () => void;
+      let finishCancellation = () => {};
+      const discovery = new Promise<void>(resolve => { finishDiscovery = resolve; });
+      activeApi.mockImplementation((...args: unknown[]) => {
+        const options = args.at(-1) as { signal?: AbortSignal; fresh?: boolean };
+        if (options?.fresh) return discovery.then(() => serverActive ? session : null);
+        if (!serverActive) return Promise.resolve(null);
+        return new Promise((_resolve, reject) => options?.signal?.addEventListener("abort", () => {
+          aborts++;
+          reject(new DOMException("The request was aborted", "AbortError"));
+        }, { once: true }));
+      });
+      cancelApi.mockImplementation(() => new Promise(resolve => { finishCancellation = () => { serverActive = false; resolve({}); }; }));
+      mockAgentsApi.getAdapterAuthSignal.mockResolvedValue({ status: "absent" });
+      const { root } = await openStep4({ adapterType });
+      const matchMedia = window.matchMedia;
+      const restoreMotion = () => Object.defineProperty(window, "matchMedia", { configurable: true, writable: true, value: matchMedia });
+      try {
+        if (panelMounted) await pickSource(claude ? /Claude/ : /OpenAI/);
+        else {
+          Object.defineProperty(window, "matchMedia", { configurable: true, writable: true,
+            value: (media: string) => ({ matches: false, media, onchange: null, addListener() {}, removeListener() {}, addEventListener() {}, removeEventListener() {}, dispatchEvent: () => false }) });
+          const tile = [...document.body.querySelectorAll('[role="radio"]')].find(tile => (claude ? /Claude/ : /OpenAI/).test(tile.textContent ?? ""))!;
+          await act(async () => (tile as HTMLElement).click());
+          expect(activeApi).toHaveBeenCalledTimes(1);
+          restoreMotion();
+        }
+        await act(async () => [...document.body.querySelectorAll("button")].find(button => button.textContent?.trim().startsWith("Back"))!.click());
+        for (let i = 0; i < 12; i++) await flushReact();
+        expect(aborts).toBeGreaterThan(0);
+        await vi.waitFor(() => expect((activeApi.mock.calls as unknown[][]).some(call => (call.at(-1) as { fresh?: boolean })?.fresh)).toBe(true));
+        expect(document.querySelectorAll('[role="radio"][aria-checked="true"]')).toHaveLength(0);
+        await pickSource(claude ? /Claude/ : /OpenAI/);
+        expect(startApi).not.toHaveBeenCalled();
+        await act(async () => finishDiscovery());
+        await vi.waitFor(() => expect(cancelApi).toHaveBeenCalled());
+        expect(startApi).not.toHaveBeenCalled();
+        await act(async () => finishCancellation());
+        for (let i = 0; i < 12; i++) await flushReact();
+        expect(serverActive).toBe(false);
+        expect(startApi).toHaveBeenCalledTimes(1);
+        expect(mockAgentsApi.hire).not.toHaveBeenCalled();
+      } finally {
+        restoreMotion();
+        finishDiscovery();
+        finishCancellation();
+        await act(async () => root.unmount());
+      }
+    });
+
     it("cancels claude_local on Back and starts a fresh sign-in when selected again", async () => {
       const session = {
         sessionId: "claude-session-1",
diff --git a/ui/src/components/OnboardingWizard.tsx b/ui/src/components/OnboardingWizard.tsx
index 29a147f8903..312e373a16a 100644
--- a/ui/src/components/OnboardingWizard.tsx
+++ b/ui/src/components/OnboardingWizard.tsx
@@ -1,3 +1,4 @@
+import { cancelAdapterLoginSession, cancelPendingAdapterLogin } from "./useAdapterLoginCancellation";
 import { useQueryView } from "@/components/QueryView";
 import type { AgentRunner, AgentRunnerChoice } from "@paperclipai/shared";
 import { needsClaudeSetupQualification, qualifyClaudeSetup } from "../lib/qualify-claude-setup";
@@ -1161,10 +1162,8 @@ function OnboardingWizardInner({
           ? await agentsApi.getActiveClaudeSetupTokenLoginSession(createdCompanyId!, { signal })
           : await agentsApi.getActiveAdapterAuthLoginSession(createdCompanyId!, adapterType, { signal });
         if (session && dismissedLoginResumes.current.has(loginResumeKey)) {
-          const cancel = adapterCaps.login?.panelMode === "submitted_browser_code"
-            ? agentsApi.cancelClaudeSetupTokenLogin(createdCompanyId!, session.sessionId)
-            : agentsApi.cancelAdapterAuthLogin(createdCompanyId!, adapterType, session.sessionId);
-          await cancel.catch(() => {});
+          await cancelAdapterLoginSession(createdCompanyId!, adapterType,
+            adapterCaps.login?.panelMode === "submitted_browser_code", session.sessionId);
           return null;
         }
         return session;
@@ -1567,7 +1566,11 @@ function OnboardingWizardInner({
   function unwindConnectStep() {
     localLogin.cancel();
     dismissedLoginResumes.current.add(loginResumeKey);
-    if (createdCompanyId) void queryClient.cancelQueries({ queryKey: queryKeys.agents.activeLoginSession(createdCompanyId, adapterType) });
+    if (createdCompanyId) {
+      void queryClient.cancelQueries({ queryKey: queryKeys.agents.activeLoginSession(createdCompanyId, adapterType) });
+      if (canShowAdapterLogin && credentialMode !== "api") void cancelPendingAdapterLogin(createdCompanyId, adapterType,
+        adapterCaps.login?.panelMode === "submitted_browser_code");
+    }
     connectAttemptRef.current++;
     hiringAgentRef.current = null;
     setLoading(false);
diff --git a/ui/src/components/useAdapterLoginCancellation.ts b/ui/src/components/useAdapterLoginCancellation.ts
index b385a9cf635..90286a6932b 100644
--- a/ui/src/components/useAdapterLoginCancellation.ts
+++ b/ui/src/components/useAdapterLoginCancellation.ts
@@ -3,6 +3,34 @@ import { useQueryClient } from "@tanstack/react-query";
 import { agentsApi } from "../api/agents";
 
 const pendingCancellations = new Map<string, Promise<unknown>>();
+const sessionCancellations = new Map<string, Promise<unknown>>();
+
+export function cancelAdapterLoginSession(companyId: string, adapterType: string, submittedCode: boolean, sessionId: string) {
+  const key = JSON.stringify([companyId, adapterType, sessionId]);
+  const previous = sessionCancellations.get(key);
+  if (previous) return previous;
+  const request = (submittedCode
+    ? agentsApi.cancelClaudeSetupTokenLogin(companyId, sessionId)
+    : agentsApi.cancelAdapterAuthLogin(companyId, adapterType, sessionId)).catch(() => {});
+  sessionCancellations.set(key, request);
+  void request.then(() => { if (sessionCancellations.get(key) === request) sessionCancellations.delete(key); });
+  return request;
+}
+
+export function cancelPendingAdapterLogin(companyId: string, adapterType: string, submittedCode: boolean, pending: Promise<unknown>[] = [], discover = true) {
+  const key = JSON.stringify([companyId, adapterType]);
+  const previous = pendingCancellations.get(key);
+  const cleanup = Promise.allSettled([...(previous ? [previous] : []), ...pending]).then(async () => {
+    if (!discover) return;
+    const session = submittedCode
+      ? await agentsApi.getActiveClaudeSetupTokenLoginSession(companyId, { fresh: true })
+      : await agentsApi.getActiveAdapterAuthLoginSession(companyId, adapterType, { fresh: true });
+    if (session) await cancelAdapterLoginSession(companyId, adapterType, submittedCode, session.sessionId);
+  }).catch(() => {});
+  pendingCancellations.set(key, cleanup);
+  void cleanup.then(() => { if (pendingCancellations.get(key) === cleanup) pendingCancellations.delete(key); });
+  return cleanup;
+}
 
 export function useAdapterLoginCancellation(active: boolean, companyId: string, adapterType: string, submittedCode: boolean, sessionId: string | null) {
   const queryClient = useQueryClient();
@@ -14,9 +42,7 @@ export function useAdapterLoginCancellation(active: boolean, companyId: string,
   const cancel = useCallback((id: string) => {
     const previous = cancelled.current.get(id);
     if (previous) return previous;
-    const request = (submittedCode
-      ? agentsApi.cancelClaudeSetupTokenLogin(companyId, id)
-      : agentsApi.cancelAdapterAuthLogin(companyId, adapterType, id)).catch(() => {});
+    const request = cancelAdapterLoginSession(companyId, adapterType, submittedCode, id);
     cancelled.current.set(id, request);
     return request;
   }, [companyId, adapterType, submittedCode]);
@@ -45,11 +71,8 @@ export function useAdapterLoginCancellation(active: boolean, companyId: string,
       ? [["claude-setup-token-active-session", companyId], ["claude-setup-token-status", companyId], ["claude-setup-token-prompt", companyId]]
       : [["adapter-login-active-session", companyId, adapterType], ["adapter-login-status", companyId, adapterType]];
     for (const queryKey of keys) void queryClient.cancelQueries({ queryKey });
-    const cleanup = Promise.allSettled([...requests.current, ...(sessionId ? [cancel(sessionId)] : [])]);
-    pendingCancellations.set(ownerKey, cleanup);
-    void cleanup.then(() => {
-      if (pendingCancellations.get(ownerKey) === cleanup) pendingCancellations.delete(ownerKey);
-    });
+    void cancelPendingAdapterLogin(companyId, adapterType, submittedCode,
+      [...requests.current, ...(sessionId ? [cancel(sessionId)] : [])], !sessionId);
   }, [active, companyId, adapterType, submittedCode, sessionId, queryClient, cancel, ownerKey]);
 
   return { accept, isActive: () => scope.current.active };