Using KDE plasma on 22.04, sddm fails to start very frequently (maybe once our of every 5 times it fails). the output from the sddm service when it fails is seen below. I can restart the service and then it works.
```
● sddm.service - Simple Desktop Display Manager
Loaded: loaded (/lib/systemd/system/sddm.service; enabled; vendor preset: enabled)
Active: active (running) since Wed 2022-05-04 10:15:07 EDT; 1min 28s ago
Docs: man:sddm(1)
man:sddm.conf(5)
Process: 760 ExecStartPre=/bin/sh -c [ "$(cat /etc/X11/default-display-manager 2>/dev/null)" = "/usr/bin/sddm" ] (code=exited, status=0/SUCCESS)
Main PID: 766 (sddm)
Tasks: 2 (limit: 19008)
Memory: 10.7M
CPU: 74ms
CGroup: /system.slice/sddm.service
└─766 /usr/bin/sddm
May 04 10:15:07 garrett-desktop sddm[766]: Initializing...
May 04 10:15:07 garrett-desktop sddm[766]: Starting...
May 04 10:15:07 garrett-desktop sddm[766]: Logind interface found
May 04 10:15:07 garrett-desktop sddm[766]: Adding new display on vt 1 ...
May 04 10:15:07 garrett-desktop sddm[766]: Loading theme configuration from ""
May 04 10:15:07 garrett-desktop sddm[766]: Display server starting...
May 04 10:15:07 garrett-desktop sddm[766]: Adding cookie to "/var/run/sddm/{078496a5-c054-4286-a48d-f76fa1eaa271}"
May 04 10:15:07 garrett-desktop sddm[766]: Running: /usr/bin/X -nolisten tcp -auth /var/run/sddm/{078496a5-c054-4286-a48d-f76fa1eaa271} -background none -noreset -displayfd 17 -seat seat0 vt1
May 04 10:15:08 garrett-desktop sddm[766]: Failed to read display number from pipe
May 04 10:15:08 garrett-desktop sddm[766]: Could not start Display server on vt 1
```
ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: sddm 0.19.0-2ubuntu2
ProcVersionSignature: Ubuntu 5.15.0-27.28-generic 5.15.30
Uname: Linux 5.15.0-27-generic x86_64
ApportVersion: 2.20.11-0ubuntu82
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: KDE
Date: Wed May 4 10:17:19 2022
InstallationDate: Installed on 2022-03-16 (49 days ago)
InstallationMedia: Ubuntu 22.04 LTS "Jammy Jellyfish" - Alpha amd64 (20220313)
SourcePackage: sddm
UpgradeStatus: No upgrade log present (probably fresh install)
I have experienced the same problem on two computers. Both new installs of Ubuntu Studio 22.04 KDE Plasma, one AMD Ryzen, the other Intel i5.
Scenario: Upon boot/reboot, login prompt appears briefly, then screen goes blank.
Recovery: type Ctl-Alt-F2, login and issue "sudo systemctl restart sddm"
Login can then proceed.
Issue: requires "administrator" priveleges to start up a computer.