I just got myself a new monitor and now have trouble with SDDM. Previous setup was a Dell U2417H connected via DP to my desktop PC. Everything was working fine. New monitor is a Dell P2423DE connected via DP to my PC. The other Dell is now daisy chained. When I boot I can see the UEFI/Bios screen and the systemd-boot menu. After that I see some kernel messages since I had to disable the splash boot option due to a bug in Neon. After that usually SDDM would come up but now all I’m getting is “no Signal” and my monitor going into standby. I have tried just typing in my password and hitting enter but without success. As soon as I switch to a different tty my monitor wakes up. I can login there and start a plasma session with dbus-run-session startplasma-wayland. I have gone into system settings and applied Plasma settings to SDDM after setting up my monitors properly. That didn’t help. System details below. Can anyone help?
Hi - it might be worth checking if there any messages in the system journal (you could use sudo journalctl --boot=0 to look at messages from the current system boot), from right around the time that SDDM fails to display, that give any clues?
And just checking, does the issue occur if you disconnect the daisy-chained monitor? How about if you connect both monitors directly to the graphics card (perhaps there’s something in the daisy-chaining somehow)?
Thanks. Daisy chaining does not seem to be the issue, it even happens with the second monitor turned off. Also weirdly sddm runs just fine when I restart it in tty.