OK, so I loaded LibreELEC-Generic.x86_64-12.0.0.img.gz and played two videos, one is H264, "A dog's life" and got green flickering screen, audio is OK. Afterwards I played "Aunty Donna's Big Ol' House of Fun" on Netflix and got color pumping, audio is OK. I've been playing before with the new option, Prime Render Method, on old installation, all possible combinations, and it didn't reduce Netflix flickering. I didn't do it now.
I've recorded a 10 seconds video of that green screen on my mobile phone, I can upload it somewhere if needed, also of the pumping, but I don't know if it will be visible as there is framerate difference... (edit, it's not visible)
Log, as requested, is here:
https://paste.libreelec.tv/valued-cougar.log
I will try Nightly, to see if there is some difference.
These are results with nightly: LibreELEC-Generic.x86_64-12.0-nightly-20240801-cbf0545.img.gz
https://paste.libreelec.tv/accurate-ferret.log
In short, nothing changed.