Unlock fail/blit sometimes on wake after sleep

[Arteneko]

I usually leave my laptop in sleep mode, or at least locked, and many times I've encountered a problem when unlocking:

I enter the right password, the greeter disappears, then suddenly reappears on fullscreen, forcing me to re-enter the password (that happens non-stop, I can't unlock my computer at this point).

The only solution to get out of this is to pkill the lock greeter from another tty, but I think that this shouldn't happen (hence probably a bug).

I don't know how to diagnose it, but my current setup is the following:

• Arch linux
• lightdm greeter
• i3 desktop environment

The auto-lock-tool is started by i3, with the command

exec_always --no-startup-id xss-lock -- dm-tool lock

[aure1is]

Same issue here. This happens only after sleep mode.
Manjaro/Arch
I start the autolock with
exec --no-startup-id xautolock -time 10 -locker "dm-tool lock"
I really like the mini theme,but it is not usable if it does not allow re-login after sleep.

//EDIT
I just found out that it somewhat has to do with the lock timer.
I was away for a little over 30 mins. When back, I entered my password, it unlocked and locked it self again just as this bug describes. However, I tried to unlock two more times. The third time it actually stayed unlocked.

It seems that the locking keeps happening although it is already locked like 3 locked stati layered on top. After 10 mins the first lock happened, then after 20 the second and after 30 the third. I had to unlock all three (after each other) to stay unlocked.

Maybe that helps in identifying the bug.