Hi, Since I haven’t seen anyone else post the resolution to this yet, but lots of people banging their heads against it:
I assume it’s related to the updates to the kde build farm that were mentioned around the time of the 23.08.2 release. The missing GLIBCXX symbols are because that release’s appimage was built with a newer libc than had been used previously and that ships with Debian 11 and derived distro releases. You’ll need to update to Debian 12 to use this appimage.
HTH,
Ron