Thank you Sam and sorry for overlooking this.
In case useful, I had to scroll down in that thead to find the actual solution, so what I did:
sudo mkdir -p /lib/firmware/edid
sudo cp /sys/devices/platform/soc/soc:gpu/drm/card0/card0-HDMI-A-1/edid /lib/firmware/edid/edid.dat
Then sudo nano /boot/cmdline.txt and append drm.edid_firmware=HDMI-A-1:edid/edid.dat video=HDMI-A-1:D