diff --git a/apps/web/src/components/pullRequest/PullRequestDetailPanel.tsx b/apps/web/src/components/pullRequest/PullRequestDetailPanel.tsx
index 7f6a4592a0b4f7f371f93827f7d25b6f0ec67898..1466e726b60fa90b3f5942908bb9e25f85df0f4d 100644
--- a/apps/web/src/components/pullRequest/PullRequestDetailPanel.tsx
+++ b/apps/web/src/components/pullRequest/PullRequestDetailPanel.tsx
@@ -823,7 +823,7 @@ export function PullRequestDetailPanel({
   const canMergeSinglePullRequest = allowsSinglePullRequestMerge({
     supportsStackActions,
     hasStack: nativeStack !== null,
-    stackPending: !nativeStackQuery.isSuccess || nativeStackQuery.isPending,
+    stackPending: !nativeStackQuery.isFresh,
     stackError: nativeStackQuery.error,
   });
   const activityPending = activityQuery.isPending && activity === null;
diff --git a/apps/web/src/components/pullRequest/pullRequestStackSnapshot.test.ts b/apps/web/src/components/pullRequest/pullRequestStackSnapshot.test.ts
index 621ba3124e8e113b3d09309d99914d08906ceee4..4b6f947232b385868cb0d765d27f53860044d16e 100644
--- a/apps/web/src/components/pullRequest/pullRequestStackSnapshot.test.ts
+++ b/apps/web/src/components/pullRequest/pullRequestStackSnapshot.test.ts
@@ -88,6 +88,10 @@ describe("saved stack navigation", () => {
       isFresh: true,
       notice: null,
     });
-    expect(pullRequestStackView({ ...query, isPending: true }, saved).isFresh).toBe(false);
+    expect(pullRequestStackView({ ...query, isPending: true }, saved).isFresh).toBe(true);
+    expect(pullRequestStackView({ ...query, data: null, isPending: true }, saved)).toMatchObject({
+      data: null,
+      isFresh: true,
+    });
   });
 });
diff --git a/apps/web/src/components/pullRequest/pullRequestStackSnapshot.ts b/apps/web/src/components/pullRequest/pullRequestStackSnapshot.ts
index 4e48a2f3705b26bb5c57c9c705ceb4e9732fbf73..a576d52c33ab5615e47089868cbd7322dc33212f 100644
--- a/apps/web/src/components/pullRequest/pullRequestStackSnapshot.ts
+++ b/apps/web/src/components/pullRequest/pullRequestStackSnapshot.ts
@@ -47,7 +47,11 @@ export function savedPullRequestStack(
   };
 }
 
-/** A fresh absence overrides saved membership; failed refreshes preserve available navigation. */
+/**
+ * A fresh absence overrides saved membership; failed refreshes preserve available navigation.
+ * A background refresh keeps the last successful lookup fresh, so stack-dependent actions do
+ * not blink out every time the detail revalidates.
+ */
 export function pullRequestStackView(
   query: {
     data: PullRequestStack | null;
@@ -60,7 +64,7 @@ export function pullRequestStackView(
   const data = query.isSuccess ? query.data : (query.data ?? saved);
   return {
     data,
-    isFresh: query.isSuccess && !query.isPending,
+    isFresh: query.isSuccess,
     notice:
       data === null
         ? null