Whenever I play animated shows in chrome, occasionally, they will skip forward at seemingly random times. It only seems to happen with animated shows. If I play the files in VLC they play fine. The ONLY thing I’ve found that works is to optimize them and then replace the original file with the optimized ones.
Use Plex For Windows or PMP.
Plexweb is crap as a Player - 'cause it runs in your browser.
Plex for Windows at the link (Apps/Devices) below.
Plex Media Player:
(if one more person compares Plexweb to VLC - I’m gonna HULK rage the neighborhood… but if they use one of the Player apps, Plex and VLC will be very similar… 'cause NONE of them run in your crappy browser…lol)