That worked! Thank you! 
Yes, I had done it before my previous post. Sorry I didn’t make it clear
Thank you @enmus and @51lieal for your help.
To recap, for others that might have the same problem. The solution is:
On dom0:
sudoedit /etc/modprobe.d/i915.conf
with this content:
options i915 enable_psr=0
And then execute:
sudo dracut /boot/initramfs-5.x.x.fc32.qubes.x86_64.img --force
Where “x.x” is your current kernel, that can be found with
uname -a
Then reboot.