Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Is there an update available for Outlook? If so, kindly update it. Also, have you tried signing in your Outlook account on a different device? This is to isolate if the issue is just happening on your mobile phone only.
We found a thread similar to your concern, kindly follow the troubleshooting steps provided by Johayber T. on this link.
Keep us posted.