If you notice the gap getting wider as it plays on that is simply a frame rate issue. You don’t mention where you got the title or what format it is in, so you’ll have to figure out what tools to use for this but, you need to:
Use MediaInfo or another tool to determine the FPS of the video stream.
Demux the file into the video and audio streams.
Remux the video and audio streams back into your container (MP4 or MKV if you’re dealing with AVC) using the correct FPS.
I used to come across things like that when I shared titles. If the video was 29.97 FPS and I muxed it at 30FPS it made all the difference. I would have to pull the share, remux correctly, and add new links.
Good luck!