I have a Librem 15v4 and I often work with an external monitor.
Plugging the monitor in via HDMI generally works fine. But some large fraction of the time (maybe 70%), unplugging the HDMI doesn’t cause PureOS to recognize that monitor has been unplugged. The computer continues acting as if it has an external monitor plugged in. I have to go to Displays and set it to Single Display to get PureOS to put all of the windows on to my laptop screen. Otherwise I have this phantom screen on which I can’t see anything!
Has anyone else encountered this issue on Debian-based systems?