Cerbo GX - can't update - 1512 You don't have sufficient rights

I know this has been reported elsewhere in the forum, but this issue appears unresolved as of April 29, 2026. I tried updating the Cerbo GX firmware using Android and desktop interfaces, but both display errors after reaching about 40% complete. See attached screenshot from the desktop session.

Is there official support for this issue? I’m logged in as my only user and I have updated the firmware in past without issue. At a loss on this.