Google tv streamer having issues with some files on my seedbox jellyfin?

I have a seedbox that has my media servers on it, specific files I try to watch on it (and my friend who has the tv streamer too) have experienced very very bad visual bugs, like it plays at like 2fps or something similar and it's unwatchable at that point. I've searched the ones I know mess up and they are all MP4 and codec x265 and the tv streamer can play those files, they play perfectly well on my PC, phone, browser etc. but it's just the streamer that messes up. I've been meaning to make a post for about 2 months now so I finally decided to do it. Does anyone know of this is fixable or is it better to return it and spend more to get a NVIDIA shield or something similar. I don't really want to get an apple tv but if I need to I can.