diff --git a/extensions/matrix/src/matrix/monitor/status.ts b/extensions/matrix/src/matrix/monitor/status.ts
index 3f101a62f00..6e5630a845e 100644
--- a/extensions/matrix/src/matrix/monitor/status.ts
+++ b/extensions/matrix/src/matrix/monitor/status.ts
@@ -90,6 +90,8 @@ export function createMatrixMonitorStatusController(params: {
         noteDisconnected({ state, at, error });
         return;
       }
+      // Unknown future SDK states inherit the current connectivity bit until the
+      // SDK classifies them as ready or disconnected. Avoid guessing here.
       status.lastEventAt = at;
       status.healthState = state.toLowerCase();
       emit();
diff --git a/extensions/matrix/src/matrix/monitor/sync-lifecycle.test.ts b/extensions/matrix/src/matrix/monitor/sync-lifecycle.test.ts
index 4c1a5f15a84..cd2d9e47f0e 100644
--- a/extensions/matrix/src/matrix/monitor/sync-lifecycle.test.ts
+++ b/extensions/matrix/src/matrix/monitor/sync-lifecycle.test.ts
@@ -62,4 +62,50 @@ describe("createMatrixMonitorSyncLifecycle", () => {
       }),
     );
   });
+
+  it("ignores unexpected sync errors emitted during intentional shutdown", async () => {
+    const client = createClientEmitter();
+    const setStatus = vi.fn();
+    let stopping = false;
+    const lifecycle = createMatrixMonitorSyncLifecycle({
+      client: client as never,
+      statusController: createMatrixMonitorStatusController({
+        accountId: "default",
+        statusSink: setStatus,
+      }),
+      isStopping: () => stopping,
+    });
+
+    const waitPromise = lifecycle.waitForFatalStop();
+    stopping = true;
+    client.emit("sync.unexpected_error", new Error("shutdown noise"));
+    lifecycle.dispose();
+
+    await expect(waitPromise).resolves.toBeUndefined();
+    expect(setStatus).not.toHaveBeenCalledWith(
+      expect.objectContaining({
+        accountId: "default",
+        healthState: "error",
+      }),
+    );
+  });
+
+  it("rejects a second concurrent fatal-stop waiter", async () => {
+    const client = createClientEmitter();
+    const lifecycle = createMatrixMonitorSyncLifecycle({
+      client: client as never,
+      statusController: createMatrixMonitorStatusController({
+        accountId: "default",
+      }),
+    });
+
+    const firstWait = lifecycle.waitForFatalStop();
+
+    await expect(lifecycle.waitForFatalStop()).rejects.toThrow(
+      "Matrix fatal-stop wait already in progress",
+    );
+
+    lifecycle.dispose();
+    await expect(firstWait).resolves.toBeUndefined();
+  });
 });
diff --git a/extensions/matrix/src/matrix/monitor/sync-lifecycle.ts b/extensions/matrix/src/matrix/monitor/sync-lifecycle.ts
index 36f60021989..13cc27d1db5 100644
--- a/extensions/matrix/src/matrix/monitor/sync-lifecycle.ts
+++ b/extensions/matrix/src/matrix/monitor/sync-lifecycle.ts
@@ -43,10 +43,11 @@ export function createMatrixMonitorSyncLifecycle(params: {
   };
 
   const onUnexpectedError = (error: Error) => {
-    params.statusController.noteUnexpectedError(error);
-    if (!params.isStopping?.()) {
-      settleFatal(error);
+    if (params.isStopping?.()) {
+      return;
     }
+    params.statusController.noteUnexpectedError(error);
+    settleFatal(error);
   };
 
   params.client.on("sync.state", onSyncState);
@@ -57,6 +58,9 @@ export function createMatrixMonitorSyncLifecycle(params: {
       if (fatalError) {
         throw fatalError;
       }
+      if (resolveFatalWait || rejectFatalWait) {
+        throw new Error("Matrix fatal-stop wait already in progress");
+      }
       await new Promise<void>((resolve, reject) => {
         resolveFatalWait = resolve;
         rejectFatalWait = (error) => reject(error);
diff --git a/extensions/matrix/src/matrix/sdk.test.ts b/extensions/matrix/src/matrix/sdk.test.ts
index 81c3cfc1ab4..8dca0eec27e 100644
--- a/extensions/matrix/src/matrix/sdk.test.ts
+++ b/extensions/matrix/src/matrix/sdk.test.ts
@@ -1070,6 +1070,36 @@ describe("MatrixClient event bridge", () => {
     await startExpectation;
   });
 
+  it("clears stale sync state before a restarted sync session waits for fresh readiness", async () => {
+    matrixJsClient.startClient = vi
+      .fn(async () => {
+        queueMicrotask(() => {
+          matrixJsClient.emit("sync", "PREPARED", null, undefined);
+        });
+      })
+      .mockImplementationOnce(async () => {
+        queueMicrotask(() => {
+          matrixJsClient.emit("sync", "PREPARED", null, undefined);
+        });
+      })
+      .mockImplementationOnce(async () => {});
+
+    const client = new MatrixClient("https://matrix.example.org", "token");
+
+    await client.start();
+    client.stopSyncWithoutPersist();
+
+    vi.useFakeTimers();
+    const restartPromise = client.start();
+    const restartExpectation = expect(restartPromise).rejects.toThrow(
+      "Matrix client did not reach a ready sync state within 30000ms",
+    );
+
+    await vi.advanceTimersByTimeAsync(30_000);
+
+    await restartExpectation;
+  });
+
   it("replays outstanding invite rooms at startup", async () => {
     matrixJsClient.getRooms = vi.fn(() => [
       {
diff --git a/extensions/matrix/src/matrix/sdk.ts b/extensions/matrix/src/matrix/sdk.ts
index 4415f736405..eaceecef873 100644
--- a/extensions/matrix/src/matrix/sdk.ts
+++ b/extensions/matrix/src/matrix/sdk.ts
@@ -536,6 +536,7 @@ export class MatrixClient {
       clearInterval(this.idbPersistTimer);
       this.idbPersistTimer = null;
     }
+    this.currentSyncState = null;
     this.client.stopClient();
     this.started = false;
   }