Login into PR4100 from Windows 10 Pro

My Cloud OS 3 Personal & Network Attached Storage My Cloud Pro Series
1

I have issue that recently user can’t access his file on my PR4100
I can login as administrator.
I can change the user password
But I am as a user can’t access my files.
I think the issue is with the Microsoft Online Account that I am using now to login to the computers.
Can someone help with some advice please

Thanks - Amit