I recently got a budget android tv iffalcon 40f2a, a subsidiary of TCL in India. I have a huge library of h265 videos, the default video player that comes out the box, plays the content without any issues, but none of the other apps like Plex, kodi, or archos is playing 1080p x265 videos. Should I change any settings? It is clear that HW support is present for x265. I have no clue on how to fix this. Your suggestions are appreciated. Thanks.
I haven't got the same box as you but maybe it would be a good idea to try asking at the Kodi, archos and plex forums?
You could also give Nova player a try also.