I'm having the same problem with version 5.15 and 5.16 than on a PC with an Athlon 64 5000+ 4GB ram and an XFX MI-A78S-8209 motherboard works wonderfully well.
But on another PC with a motherboard ITX Asrock AD525PV3 with 2GB ram I have the same black screen after the boot.
Strange that using batocera v.5.2.0 or the latest version of the recalbox in both but machines works perfectly.
Pressing CTRL + F4 on the black screen takes me to a screen that I do not know and I have also edited the grub.conf file but the black screen is still there only on the PC with the ITX motherboard.
I do not know what to do. (sorry for my English).