You can reproduce this by running muvm -it bash in a terminal, and then launching steam.

Steam will launch just fine, but the window indicating that we're waiting for steam to launch closes almost immediately. Looks like it thinks steam quit immediately. (Would it help to use muvm -i when launching steam?)

logs from running steam in a terminal under these circumstances

Steam quit
QSettings::value: Empty key passed
Aborting
Qt says we're gone, aborting=True