The new lxqt-session package (version 2.1.0-3) from the Galaxy (https://packages.artixlinux.org/packages/galaxy/x86_64/lxqt-session/) repository seems to be depending on libproc2.so=0-64. This leads to not being able to login to the LXQt session, as libropc2 is on version 1-64.
The Arch package from the Extra (https://archlinux.org/packages/extra/x86_64/lxqt-session/) repository is in fact depending on libproc2.so=1-64 and installing that package instead of the one from the Artix repository solves the problem.
I don't know if this is an error from the maintainer or if I'm missing something. Anyway I think this is worth mentioning, just in case anyone encounters the same problem.
lxqt-sessions has been updated now; pls report back after you have been able to install and test it.
artist
I can confirm it is now working, thanks!