PermissionError: [Errno 13] Permission denied:

i can successfully install erp next via docker. always runs with no issues.
if i make a backup of the volumes using duplicati, and restore them, i get the following error inside the frontend container when restarting the containers.

PermissionError: [Errno 13] Permission denied:

am i correct that it is a user or password error?
And why would this change? it is basically a backup of a working default installation restored back onto the same docker?