even after adding that line it still shows that I am part of root

@include common-auth

be the two lines

@include common-auth
auth optional pam_group.so

I'm hoping that might make the login procedure via sddm more aligned with the procedure of tty login and in particular add a pam_group.so call that seems to be missing. Though it's kind of an untested wild guess so don't hold your breath.

Since using

rc-service sddm restart

makes you root the only workaround is to reinitiate everything, so on a true tty (Alt+F1-F6):

# telinit 1
...(go into runlevel 1, and then exit)
# exit

It's bad and probably not the best solution but I don't know how else to solve this problem, so for now, i'll simply restart pid 1

Important note - Do not perform telinit 1 (or any "sudo telinit ...") on a GUI terminal (QTerminal and so), do it on a regular tty because sddm breaks it and it won't send you back to a functional tty... (or is it just on my system?)

Again - this isn't a good solution, as it really messed my tap interfaces for incus...

It is also worth to mention that: If you sent yourself into single mode (

# telinit s

) and then you're accidentally pressing f2-f7 to switch tty, all ttys will freeze including the single-mode one and become non-functioning, and then you won't be able to do anything except for magic sysrq (s+u+b) to force-reboot the machine

There's a problem I'd like to inform you about.
Maybe it's something in my configuration? Perhaps it's global?

Using sddm (LXQt), Services managed by OpenRC

Whenever you restart sddm, Regular users are being added to the root group.

Before, on any tty/psudeo-terminal:

$ groups
user cdrom floppy sudo audio dip video plugdev users netdev bluetooth lpadmin scanner incus-admin

After:

On regular tty:

$ sudo rc-service sddm restart

On GUI psuedo-terminal (QTerminal):

$ groups
user root cdrom floppy sudo audio dip video plugdev users netdev bluetooth lpadmin scanner incus-admin
$ id
uid=1000(user) gid=1000(user) groups=1000(user),0(root),24(cdrom),25(floppy),27(sudo),29(audio),30(dip),44(video),46(plugdev),100(users),105(netdev),109(bluetooth),111(lpadmin),114(scanner),995(incus-admin)

Worth to mention that:
The user is part of the root group only on GUI terminal (within LXQt) and not on regular ttys (if you'll run the groups command on a regular tty, this won't happen)

How can I fix it?

Update - I found out that it is a well known bug since 2018(!) how sad