Hi, I am running Debian Testing with two monitors in portrait mode. I never had a problem with this configuration.
This week, I received a desktop notification telling me that there were updates available that required a reboot. I proceeded, and after the reboot and after introducing my password to enter my session, I got both monitors with black displays, apparently unresponsive.
Ctrl-Alt Fn5 would at least give me a command line (in landscape mode). With this I ran update & upgrade, but packages were all fine.
After trying different things, I created a new user, and then rebooted. With the new user I can log in and I get a GNOME desktop alright (in landscape mode). If I select a display and rotate it, that display will go black.
I have searched for this problem, but the keywords won't help to get results related to this specific problem. Any ideas?