Disk password prompt - no video signal after a couple of seconds

[philipandag]

Qubes OS release

Qubes OS 4.2

Brief summary

HP t630 v2 thin client,
CPU: AMD GX-420GI
Qubes 4.2.3, EFI boot

The disk is encrypted. During booting the disk encryption password prompt appears, and after a couple of seconds the video signal is cut off. Everything else seems to be working fine because:
a) entering the password quickly, before video is lost results in QubesOS booting properly
b) entering the password blindly after the video signal is lost also results in QubesOS booting properly

After the password is entered the video signal is brought back and everything works fine.

HP t630 has two Display Ports. I've tried plugging a monitor to both of them. The video is duplicated on both monitors and the signal is lost simultaneously on both.

dom0 is up to date:

[qubesos@dom0 ~]$ sudo qubes-dom0-update
Using sys-firewall as UpdateVM for Dom0
Downloading updates. This may take a while...
Fedora 37 - x86_64                               13 kB/s | 6.0 kB     00:00    
Fedora 37 - x86_64 - Updates                    9.6 kB/s | 5.9 kB     00:00    
Last metadata expiration check: 0:00:01 ago on Thu Jan 23 08:55:59 2025.
Dependencies resolved.
Nothing to do.
Complete!
No packages downloaded
Qubes OS Repository for Dom0                                                                                    2.7 MB/s | 3.0 kB     00:00    
[qubesos@dom0 ~]$ 

Steps to reproduce

1. Boot the QubesOS drive
2. Select the QubesOS, with Xen hypervisor boot entry in Grub
3. Wait for the disk encryption password prompt to appear
4. Wait a couple seconds more

Expected behavior

The video signal should not be cut off.

Actual behavior

The screen goes black. The monitors show "no signal". Video won't return even after 5+ minutes unless the disk password is typed in, followed by Enter. The login screen will then appear after a while.

Additional information

journalctl -b
HCL report

[alimirjamali]

What happens if you press ESC key when the monitor shows "no signal"?