VobSub Subtitles do not Properly Sync and Repeat Sentences - Roku App and Plex Player

I am transferring my DVDs to mp4 or mkv files using MakeMKV and Handbrake. I am including forced foreign subtitles and pick the english subtitles as the default in Handbrake and do not burn them in. I am using Plex version 1.431.10611 on a desktop Intel setup. I can provide more technical details, if needed.

The files play the vobsub subtitles fine using vlc player for both mp4 and mkv and also using the Plex Android app on my phone with the mkv file. However, when using a Firefox browser on my desktop to play in Plex and also using the Plex app for Roku TVs or a Roku stick, they start off fine but quickly start repeating and/or getting out of sync with either file type.

I recently reinstalled the plex server to a new and more powerful desktop computer and transferred the prior settings. I did check the “Enable Voice Activity Detection” initially after moving it. When I ran into this problem, I unchecked it before transferring both an mkv and mp4 file version of an episode of Vera as a test and the problem still existed.

Once in a while, I had a sync problem on the prior server. Now it the problem occurs with almost every dvd I transfer. Is there a Plex server setting(s) I need to change?

I have uploaded the recent server and transcoder statistics.

Thanks,

Roy

Plex_Transcoder_Statistics[1].log (261.7 KB)

Plex_Media_Server[1].log (3.2 MB)