File Names change, permissions are dropped when copying files within MS Teams or Share Point Online

Hello,

Please can you help.

I am new to MS Teams and MS Share Point Online and don't have administrative permissions.

When I copy a batch of files (docx, pdf & xlsx) within MS Teams or from MS Teams to Share Point Online, the destination file names are changing, the permissions alter (EveryOne) and (System) is dropped.   Also metadata from the files, post copy operation, is lost.  An error exception message is thrown: " A requested file could not be found at the time an operation was processed".

The directory structure is 5 levels deep and there are long file names.  I am using Word 2016 on Windows 10 Pro.  If I copy the same files to another network drive where I am not using MS Teams or Share Point Online the files copy normally.

I don't have an admin account in Share Point or Teams to see of that makes a difference.  I am told the default settings/policies are applied. No configuration has been done.

What can I do to troubleshoot this issue and is anyone else having the same problem?

Is a GPO needed? If so where? Or registry key need changing?

Thank you.