Microsoft To Do known issues and what to check

If Microsoft To Do is showing sync delays, missing reminders, disappearing tasks, or app crashes, it’s usually either a temporary Microsoft service issue, a device-specific problem, or a setting/account issue on your side. The safest first checks are to open the web version, refresh the app, and then sign out and back in if the problem keeps showing up. That usually tells you quickly whether you can fix it now or whether it’s a known issue worth waiting out.

Symptom

Tasks, reminders, or changes appear on one device but not another

This usually shows up after a sync delay, a weak connection, or a local app problem. You may notice it after adding, completing, or moving a task, or when a reminder should fire but doesn’t.

The exact message varies. Some people don’t get an error at all; they just see tasks missing, lists stuck loading, reminders not firing, or the app crashing when it opens.

Before you start

This applies to Microsoft To Do on the web, Windows, iPhone, iPad, and Android. The steps below do not require Administrator or sudo access unless your device or work policy asks for it when you change app or notification settings.

You do not need to restart or back up anything before the first checks. Start with the safest, most reversible steps: compare the web app with the device app, and confirm whether the same problem shows up on more than one device.

If you use a work or school account, your organization may also have Microsoft 365 service health information in the admin center. If you are not an admin, use the web app as your baseline and compare devices before you change anything major.

What Microsoft To Do issues people keep running into

The most common problems are sync delays, missing tasks, reminders that don’t fire, and the app freezing or crashing when it opens. Sometimes a task appears on one device but not another, or it shows up with a different due date, list, or reminder time after syncing.

You may also see tasks disappear from a list and then reappear later, especially after a poor connection or a background sync failure. On mobile, the app can fail to load notifications even though the task itself is still there. On desktop or the web, the page may stay stuck on loading, or recent changes may not appear until you refresh.

A few symptoms point to settings rather than a broken app. A reminder that never arrives can come from notification permissions, Focus Assist/Do Not Disturb, battery optimization, or a calendar conflict. If the app opens but only one list misbehaves, that can be a local data problem rather than a full service outage.

When it’s a known issue and when it’s just your setup

Start by checking whether the problem happens everywhere or only on one device. If the same task is wrong in the web app, on your phone, and on your PC, that leans toward a sync or service issue. If it only happens on one device, it’s more likely a device setting, app cache problem, or an outdated app version.

Before you do anything invasive, do two quick checks:

• Open Microsoft To Do in the web browser and compare it with the app.
• Check whether other Microsoft services are also slow or failing for you.

If the web app matches the problem on your device, the issue is less likely to be just a phone or PC setting. If the web app looks fine while one device is wrong, focus on that device’s app, cache, notifications, and network first.

A few clues help separate the cases:

• Known service issue: the web app and multiple devices are wrong in the same way.
• Device-specific bug: only one phone, tablet, or PC is affected.
• Account or settings issue: the app works after you sign out and back in, or notifications start working after you fix permissions.
• Connection issue: changes appear only after you reconnect to the internet or switch networks.

The safest fixes to try first

Start with the least risky steps. These won’t normally remove your tasks, and they often clear up sync problems quickly.

1. Refresh the app or browser. Close Microsoft To Do completely, then reopen it. If you’re using the web app, reload the page. ``text title="Settings path" Microsoft To Do > close the app or browser tab > reopen `` If the tasks update, the issue was probably a temporary display or sync delay. If nothing changes, move on.
2. Check your connection and try a different network. Make sure the device is online and can reach other websites or apps. If the problem started on Wi‑Fi, try mobile data or another network. ``text title="Settings path" Device network settings > Wi-Fi or mobile data > switch connection `` If the app starts syncing again, the network was blocking or delaying updates. If not, the issue is elsewhere.
3. Update Microsoft To Do. Install any pending app updates from your app store or device update system. Old versions can break notifications or sync. ``text title="Settings path" App store > Microsoft To Do > Update `` If there’s no update available, that doesn’t mean the app is current enough to rule out a bug, but it does remove one common cause.
4. Sign out and sign back in. This often forces a fresh sync with your Microsoft account. ``text title="Settings path" Microsoft To Do > Settings > account/profile > Sign out `` Sign back in with the same account after that. If tasks appear normally again, the issue was likely a stale session or account sync problem. If some items are still missing, check the web app before going further.
5. Check notifications and reminder settings. If reminders are the problem, confirm the app is allowed to send notifications and that your device won’t suppress them. ``text title="Settings path" Device settings > Notifications > Microsoft To Do > Allow notifications `` Also check battery-saving or focus modes that may silence alerts. If notifications are allowed but reminders still don’t appear, the problem may be tied to the specific task or to the account sync state.
6. Clear the app cache or reinstall the app. Use this only after the simpler steps above. Clearing cache can help with corrupted local data; reinstalling refreshes the app files without changing your account data. ``text title="Settings path" Device settings > Apps > Microsoft To Do > Storage > Clear cache `` If your device doesn’t offer a cache-only option, uninstall and reinstall the app instead. If the problem survives that, it’s less likely to be a local app file issue and more likely to involve your account or Microsoft’s service state.

Where to check whether it’s a known Microsoft issue

Check the Microsoft To Do web app first, because it gives you the cleanest comparison with your device. If the web app has the same missing tasks, wrong dates, or sync delays as your phone or PC, waiting is often better than chasing settings.

For work or school accounts, check the Microsoft 365 service health information in the admin center if you have access. If you do not have admin access, compare the web app with your device app and look for a broader Microsoft service incident before assuming the problem is only on your device.

If other Microsoft services are also acting up for you at the same time, that is another clue that the issue may be on Microsoft’s side rather than in your app settings.

How to check whether it’s working again

The best proof is not just that the app opens, but that changes show up the same way everywhere you use it.

Use these checks:

• Add a new task in the app, then confirm it appears in the web version.
• Mark a task complete on one device, then make sure it updates on the others.
• Set a reminder for a near-future time and confirm the notification arrives.
• Check that the same list order, due date, and reminder details match across devices.

If a task shows up in the web app but not on your phone, the phone is still not syncing correctly. If reminders work on the web but not on one device, that device’s notification settings are still the likely cause. If everything matches after you sign back in or update the app, you probably fixed a local sync or session problem rather than a broader Microsoft issue.

If the app was crashing, reopen it a few times after the fix and confirm it loads normally each time. A one-time successful launch is good, but repeated stable launches are a better sign that the problem is gone.

What to do if the same problem keeps coming back

If the issue keeps returning after the basic fixes, the next step is to narrow down where the failure happens.

First, test another device or the web app. If the problem only shows up on one phone or PC, that device still has a local setting or app-state problem. If it happens everywhere, you’re probably dealing with an account sync issue or a Microsoft-side problem.

Then review the device settings that most often interfere with To Do:

• Notification permission for the app
• Battery optimization or background app limits
• Focus Assist, Do Not Disturb, or quiet hours
• Time and date settings on the device

Reinstalling the app is fine, but don’t start deleting your Microsoft account, resetting the whole device, or wiping app data unless you’ve already confirmed your tasks exist in the web app.

If tasks still disappear or show up differently after all of that, gather the details before you contact Microsoft support: the device type, app version, whether the problem happens in the web app, what changed just before it started, and whether reminders, task order, or full lists are affected. That makes it much easier to tell whether you’re reporting a known service issue or a local sync problem that needs a deeper look.

Conclusion

If the web app, your phone, and your PC all disagree, stop chasing device fixes and check for a Microsoft-side issue. If only one device is wrong, work back through the safe steps above: update, sign out and back in, check notifications, and clear or reinstall the app if needed. If you’ve already done that and the same tasks still vanish or sync inconsistently, contact Microsoft support with the exact behavior and which devices are affected.

Frequently Asked Questions

Does Microsoft To Do have a status page for outages?

For work or school accounts, check the Microsoft 365 service health information if you have admin access. If you don’t, compare the web app with your device apps; if all of them fail in the same way, that points more toward a service issue than a local bug.

Why do my Microsoft To Do reminders not fire?

The usual causes are notification permissions, Do Not Disturb or Focus modes, background restrictions, or a reminder that never synced correctly. If the task exists in the web app but the alert never appears on one device, check that device’s notification settings first.

Why do tasks disappear from one device but not another?

That usually means the device is behind on sync or has stale local data. Refresh the app, sign out and back in, then compare the web app with the device that missed the task.

Is reinstalling Microsoft To Do safe?

Usually yes, as long as your tasks are already stored in your Microsoft account and you can see them in the web app. Reinstalling affects the local app, not the cloud copy of your lists.