@raphael-bueno-hatencia
At least I know is related to L2.
Sorry, but, have you tested the idea of changing the HDMI CEC?
You didn't make that clear, and you made it look like you dismissed that possibility without testing.
Please test, it may be related even if it doesn't seem to make sense. It is possible that there is some conflict between a driver, and that kind of situation really shouldn't happen.
To test, you only need to make 1 change to 1 file, you can back up the file beforehand if you prefer, or you can just manually return to the original configuration later if it doesn't work, but you need to test.
There are not many reports about this problem, and none has a solution described, and, as I don't have this problem, I don't know how to help a lot, in these situations, it is necessary to test all possibilities.