I plugged my Steamdeck into my usb-c dock and set the primary display to the secondary monitor and switched the built in screen off. When it finished, the launcher bar disappeared and so did the ability to set it as the primary display. Unplugging, has the same issue but with the built in display. I recently re-imaged the deck because I have been distro hopping on it. This is the first time I’ve been in the desktop mode since re-imaging. It’s been working fine in gaming mode for the last few weeks.