Onedrive issue

Question

Hi,

one of users in our office has issue to upload attachment in Teams
when user tries to upload file on Teams

it says :

unable to connect to onedrive. Please try uploading again.

and when user tries to save file on onedrive,

it says :

this files is read-only
you need to be given permission to this file to sync it.

further, when user logs into Onedrive Mobile and Web based onedrive.

like below pic, Username on the left top side navigation bar is incorrect. it shows previous manager name
it's weird, and we tried it using other laptop, however it's same as user mobile, laptop.

Please note that this user was resigned last year and re-hired in this year.

Could you please help us to resolve this issue.
our infrastructure team has checked this before, but they said all setting and what they configured are correct and all things looks good.

Please let me know what is making this issue

and what part of Azure AD system do we need to check again?
AD account? Azure onedrive configuration?

Thank you.