Can't copy file between Sharepoint sites "one or more errors occured"

This used to work fine but last few days when trying to copy a file from one site to another it fails saying "one or more errors occurred". It gives no other detail.

Permissions are all fine between sites. Can copy files fine in the same site. All sites using the same modern experience.

Just when copying a file from one site to another it fails, or moving.

Any idea as the error message is giving me nothing as to why this isn't working

Thanks