Comment # 2 on bug 1187566 from Anonymous User

I have done some more testing with kernel 5.12.12-lp153.3.1.g43254cf-x86_64
from Kernel:stable:Backports an obtained some interesting results:

With the default 5.3.18 kernel, the monitor will awake from standby one out of
four times during startup. (So the issue seems to be dependent on some timing,
which in turn might affect the order of parts of the boot sequence.)

With the 5.12.12 kernel, the monitor will awake from standby three out of four
times during startup. When the monitor awakes, one of the following happens:
1) The monitor awakes while the splash screen is displayed. In this case
startup will finish and everything works as expected.
2) The monitor awakes while both my notebook's BIOS logo and the Leap logo are
still being displayed, which happens before the actual splash screen is being
displayed. In this case the system will hang and startup will not proceed any
further. If I unplug my docking station, startup will continue. If i reconnect
my docking station after startup is completed, the monitor will be detect and
awake from standby after boltd authorizes the docking station. (This is the
issue that I have already observed back when I was using openSUSE Leap 15.2
with the default kernel except that I was using a udev rule instead of boltd,
as mentioned above.)

So there seems to be an improvement with a more up-to-date kernel but the issue
is not fully resolved yet.