I have plex server setup on my NAS (synology 1515+) and my client is on an Amazon Fire TV 4k. Everything ran fine till a few weeks ago playback randomly stops. How can I fix this? I have updated the server to the latest version available.
Have you checked to see if the videos are transcoding?
in most cases no transcoding, sometimes audio is transcoded. I think my sinology is too under powered for video transcoding anyway.