Videos won't restart if subtitles are selected.

Hi

I use Plex on an AppleTV when I try to resume playback of videos when subtitles are selected I see a black screen start and it continuously loads and never starts. If I turn the subtitle off it starts properly and if I restart from the beginning and scan to the location with the subtitles it works as well.

What could be causing the playback to not work properly it used to work fine?

Thank you