Plymouth-quit-wait.service does not stop, boot does not finish

It seams that I do have this with the Laptop where I still use Mate desktop.
I Upgraded from F38 to F39. While rebooting I get the plymouth-quit-wait.service shown and a blinking screen.

Tomorrow I will try the solution from Arch Linux (see link below):

You might try running plymouth quit manually as root - if that causes plymouthd to exit and systemctl status to transition to State: running, then the problem is about plymouth quit not getting executed automatically. If the state does not change, then try killing the plymouthd process, as it seems to be hung somehow.

The second problem I have is a bad one, missing Realtek drivers for the newer Kernel 6.5.12 - 6.6.2.
so I have to search a solution there too. I am not alone with this Issue.

No chance to interrupt the blinking screen. Ctrl & Alt F2 not works, alias it shows up but switches back to the message screen.
I do not know what else I could do?

In emergency mode I can check the status of the plymouth services and it shows an orange message saying:

systemd[1]: /usr/lib/systemd/system/plymouth-start.service:15:
Unit configured to use KillMode=none.
This is unsafe, as it disables systemd's process lifecycle management for the service.
Please update your service to use a safer KillMode=, such as 'mixed' or 'control-group'.
Support for KillMode=none is depreceated and will eventualy be removed.
cat /usr/lib/systemd/system/plymouth-start.service

Description=Show Plymouth Boot Screen
Wants=systemd-ask-password-plymouth.path systemd-vconsole-setup.service
After=systemd-vconsole-setup.service systemd-udev-trigger.service systemd-udevd.service

ExecStart=/usr/sbin/plymouthd --mode=boot --pid-file=/run/plymouth/pid --attach-to-session
ExecStartPost=-/usr/bin/plymouth show-splash

It is already on KillMode=mixed. It is also this way on my desktop machine where I not have issues with F39

I am not exactly sure how the relation from lightdm and plymouth are. But it looks like because of a change of the dependency, lightdm was not starting anymore (after update F38-39) and plymouth displayed an error of depreciation.

Probably just a bad coincidence ?!

I will close this Request and link to the issue with lightdm.