Thank you for the confirmation (that it’s not just this AM8 Pro device that won’t work). Is the first one something that needs to be addressed via code or something that can be just configured? Such material is quite common with any old TV shows in my library.
I wonder if these cases are related to what was mentioned in one S905X4 thread not long ago (Report about Amlogic S905X4 HK1 RBOX X4 - #914 by presskopf). AV1 hardware decoding seems to have its teething issues.