[RPi4] Can not set higher resolution than 1024x768 after update

Running on RPi4, Libreelec 12, in the updates section I checked the Bootloader EEPROM option.

After reboot, the resolution went down to 1024x768p and I cannot set it to any higher resolution. Had it running on 4k before the update.

Any ideas?

I changed the gpu_mem to 256. After restart I get an error 'Ungültiges Format' (Invalid Format), but I have my video modes back.

Changing gpu_mem back to 78, the error message is gone and I still have all video modes available.

But everything above 1980p is only shown in the upper left corner of my screen