Hi
I’ve found that Plex has a narrow acceptance of h.265, an increasingly popular codec that is beginning to push out h.264 as the preferred format. Plex states that it does support but only if it is: mp4, 8bit, and other requirements. But I’ve found that even if the file meets that criteria, it still doesn’t play well (or at all)
If you would like to see PLEX accepting h265 to a greater degree, please vote here: Please expand your acceptance of H.265
And if anyone has found a workaround, please share.