Hi, I'm Joshua and I am happy to help.
Sorry to hear you're experiencing this issue!
Here are a few steps to try to resolve your issue:
- Confirm the person you added has permission to access the "Lists" tab and "Assigned Tasks".
- Make sure the "Assigned Tasks" feature is enabled in the Microsoft Teams settings.
- Try creating a new item in the "Lists" tab and assigning it to the person to see if it appears in "Assigned Tasks".
- If the issue persists, try clearing your browser cache and cookies, or using a different browser.
Let me know if you need further assistance.
Regards,
Joshua.