This does sound like a browser compatibility issue.
1. Could you check your portal log to see which exact call triggers the error? You can find portal log at <install root>\PBIRS\LogFiles\RSPortal_<date>.log.
2. Have you set item specific permission to the mobile report? If so please try to make it inherit from parent folder and try again.
3. Could you try to download the report and re-upload in Chrome, then try to render/edit/delete in Edge, to see if this solves the issue?