I have a bit of a few things going wrong that seem to be all related. Odroid C2, LE 12 nightlies.
Issues started popping up a few weeks back.
First issue, the system would often be found with a non-responsive GUI after it had been left idle, so screen saver active and eventually display shutdown. The display would turn back on, so CEC was still working, but the GUI would be frozen. Sometimes you could here the remote "clicks", but still the GUI was frozen. This sounds like https://github.com/LibreELEC/LibreELEC.tv/issues/8488 however I haven't any of those EGL errors.
Second issue that started at the time was glitchy video playback IF using hardware acceleration. Basically, every so often, randomly, the frames momentarily freeze and/or are rendered in the wrong order. Truly random, the glitches don't occur in the same places when re-watching the video. Switching it to purely software decoding, either PRIME or EGL, and the issue appears to go away. Considering it had previously been working fine until sometime in December, and the randomness of it, could this be a timing issue that the EGL fence causes?
The following is a log where a video was started and had some glitches within the first few minutes then playback was stopped,
I'm still trying to get a log from the frozen GUI