Okay… I was annoyed and
I’ve just reinstalled everything 
and I found the issue! Finally
The trouble is that when I enable the driver for the Pimoroni HyperPixel screen it hangs at boot!
As soon as I add to config.txt
dtoverlay=vc4-kms-dpi-hyperpixel4,rotate=270
dtoverlay=vc4-kms-v3d
The boot hangs for 2 minutes. I have no idea why. Just comment the lines above and it starts in few seconds (but obviously the screen doesn’t work without the two lines/drivers).
I see from the changeling that you @MichaIng have changed something in raspberrypi-sys-mods with 8.9. So this is the issue:
The
raspberrypi-sys-mods packagehas been replaced with an own one, using only the small subset of the contained tweaks, which are useful on DietPi as well. A recent update of the package added a large number of dependencies, required for rpi-imager setup steps on Raspberry Pi OS only: MichaIng/DietPi#5734
If you want I can help you to investigate the issue, reporting logs, info, etcc… but at least I found the issue.
I can wait two minutes at boot, there’s no problem, I reboot it once in months but this issue should be fixed, because it can cause issue also with other displays I think!
tvservice is not supported when using the vc4-kms-v3d driver.
