If your Microsoft account keeps asking for a password multiple times a day, then it is mostly because the security has doubts about your account and there is something that triggers a check.

first log in to your Microsoft account. Then, navigate to the Security tab and click Change my password. Verify your identity ...

If that doesn’t work, then try these methods: Verify Account Credentials Convert Local Account to Microsoft Account in Safe Mode with Networking Check if Microsoft Accounts are Blocked in Local ...