diff --git a/src/web-server/usage/native-quota-collector.ts b/src/web-server/usage/native-quota-collector.ts
index 65b20820..3d4517e4 100644
--- a/src/web-server/usage/native-quota-collector.ts
+++ b/src/web-server/usage/native-quota-collector.ts
@@ -669,6 +669,26 @@ function markDefault(row: BarSummaryRow, isDefault: boolean): BarSummaryRow {
   return { ...row, is_default: isDefault };
 }
 
+/**
+ * Tag the row with is_default AND write the flag back onto the cached copy. The
+ * collector caches a row before the default profile is known (the default is
+ * resolved in the enumerator), so without this the cache-fallback path
+ * (getCachedNativeAccountRows) would serve the default account with
+ * is_default:false and the UI would stop ordering/tagging it as the default.
+ */
+function markDefaultAndSyncCache(
+  map: Map<string, ProviderState>,
+  profile: string,
+  row: BarSummaryRow,
+  isDefault: boolean
+): BarSummaryRow {
+  const state = map.get(profile);
+  if (state?.cachedRow) {
+    state.cachedRow = { ...state.cachedRow, is_default: isDefault };
+  }
+  return markDefault(row, isDefault);
+}
+
 async function collectClaudeRowForProfile(
   profile: string,
   deps: NativeQuotaDeps,
@@ -1453,7 +1473,7 @@ async function getNativeAccountRowsMultiProfile(
     const isDefault = p === claudeDefault;
     tasks.push(
       collectClaudeRowForProfile(p, deps, force)
-        .then((r) => (r ? markDefault(r, isDefault) : null))
+        .then((r) => (r ? markDefaultAndSyncCache(claudeProfileStates, p, r, isDefault) : null))
         .catch(() => null)
     );
   }
@@ -1462,7 +1482,7 @@ async function getNativeAccountRowsMultiProfile(
     const isDefault = p === codexDefault;
     tasks.push(
       collectCodexRowForProfile(p, deps, force)
-        .then((r) => (r ? markDefault(r, isDefault) : null))
+        .then((r) => (r ? markDefaultAndSyncCache(codexProfileStates, p, r, isDefault) : null))
         .catch(() => null)
     );
   }
diff --git a/tests/unit/web-server/native-quota-collector.test.ts b/tests/unit/web-server/native-quota-collector.test.ts
index 3022f478..2700e3bf 100644
--- a/tests/unit/web-server/native-quota-collector.test.ts
+++ b/tests/unit/web-server/native-quota-collector.test.ts
@@ -1306,4 +1306,32 @@ describe('review focus areas: reauth caching + codex local fallback', () => {
     expect(localCalls).toBe(1);
     expect(def?.quotaStatus).not.toBe('unsupported');
   });
+
+  it('cache-fallback rows keep is_default for the default profile', async () => {
+    resetNativeQuotaState();
+    const clock = { now: 6_000_000 };
+    const deps = makeMultiProfileDeps({
+      clock,
+      claudeProfiles: ['work', 'ck'],
+      codexProfiles: ['default', 'ck'],
+      claudeDefault: 'work',
+      codexDefault: 'default',
+      credsForProfile: () => maxCreds(),
+      claudeFetch: async () => successQuota(),
+      codexNativeAuth: (p) => ({ accessToken: `t-${p}`, accountId: `id-${p}` }),
+      codexNetworkFetch: async () => codexSuccessQuota(),
+    });
+
+    await getNativeAccountRows(deps); // populate the per-profile caches
+
+    // The cache-fallback path must preserve is_default so the UI still orders and
+    // tags the default account when /summary serves from cache.
+    const cached = getCachedNativeAccountRows();
+    expect(cached.find((r) => r.surface === 'ccs' && r.profile === 'work')?.is_default).toBe(true);
+    expect(cached.find((r) => r.surface === 'ccsx' && r.profile === 'default')?.is_default).toBe(
+      true
+    );
+    expect(cached.find((r) => r.surface === 'ccs' && r.profile === 'ck')?.is_default).toBe(false);
+    expect(cached.find((r) => r.surface === 'ccsx' && r.profile === 'ck')?.is_default).toBe(false);
+  });
 });