OneDrive Sync fails due to "unauthenticated" -Error

Hi,
OneDrive Sync worked for ~1 year, now it keeps failing with the Error: “failed to open source object: unauthenticated: Unauthenticated”.
Dry run always comes back successful. It sees the files, but is unable to copy them. The credential is also verified as valid.

Using TrueNas Core version: 13.0-U6.2

Does anyone have an idea?