Hi, I'm Ric, an independent advisor. I'm sorry you're experiencing this issue. Have you noticed when the sync stopped? Was it after an update, or did it just one day refuse to show new items?
Are any newly created tasks showing in Planner? That tells us whether Planner sync is working but To Do isn’t or if Loop isn’t even pushing to Planner.
In the meantime, let's check some of the common issues:
- Task-list creation method
Loop task-lists will only sync if they’re created using the built-in Task list component (sometimes called the “Task List Template”). If you added to Loop in some other way, Planner and To Do won’t pick them up. Make sure you’re inserting a Task list via / > Task list in Loop. Learn more here https://support.microsoft.com/en-us/office/mana...
- App versions & updates
Syncing is still in preview; mismatched versions between Loop, Planner, Teams, and To Do can block the bridge. Head to each app’s settings and check for updates in the Microsoft Store or via your org’s deployment tool.
- Only tasks assigned to you will show up in Assigned to me in To Do. Double-check that the person you tag matches a valid Microsoft 365 user in your tenant, and that you’ve got the right work or school account signed in.
- If everything’s wired correctly, a quick sign-out/in of the To Do and Loop apps (or clearing their cache) often jump-starts that first sync.
Let me know the details so I can assist you further.
