HDMI-CEC seems to stop working after a couple of hours

It’s a full re-install that’s required unfortunately.

The latest image that is not affected by the issues (for the Vero 4K/4K+) is here: https://ftp.fau.de/osmc/osmc/download//installers/diskimages/OSMC_TGT_vero3_20220314.img.gz

After installation/first run, you should also aim to comment out the “deb http://apt.osmc.tv buster main” line in your /etc/apt/sources.list too so that you don’t accidentally accept any further updates if you want to stay on this older release…