[Solved] Splash only appearing on startup, not on shutdown

[LouisGuo]

Whenever I shutdown my Thinkpad T14, no splash screen is displayed. Instead, there is initially a blinking cursor which, after a delay, shows "watchdog did not stop!" This problem only occurs on shutdown, and the splash appears correctly when starting up Debian. I'm not sure when or why this started. Is there any way to restore the splash on shutdown?

[LouisGuo]

After some debugging, I've gotten further from understanding what the problem is. The splash screen appeared a few times when rebooting, but now no longer appears. There may not be a problem at all, but rather the computer shuts down too quickly for the splash screen to appear. Here is a pastebin link to plymouth-shutdown-debug.log after a shutdown with no splash screen:
https://pastebin.com/AcWvWb6k

[LouisGuo]

After a few more reboots, it seems like it's completely random as for whether or not the splash screen will appear, but I'm not completely sure. Since I forgot to mention it, I'm using Debian 12 with GDM.

[LouisGuo]

For future reference, I resolved the issue by recommenting the line "WaylandEnable=false" in "/etc/gdm3/daemon.conf", which I uncommented before to solve https://askubuntu.com/questions/1481598 ... ks-firefox.
In addition, adding "plymouth:debug" to "GRUB_CMDLINE_LINUX_DEFAULT" "/etc/default/grub" appears to sometimes cause the splash screen to appear when Wayland is disabled.