Resumed videos always begin at the start
For a while now every time I return to a film I'm watching from the Plex on my computer, the web player will ask, "Resume from 38:10" or whatever. But, when I select the time, it will briefly show the progress bar filled in to the appropriate time, only to be immediately reset to the start and the film starts from the beginning.
If I resume the same film on my phone or if I start it on my Chromecast it resumes correctly. Is this a bug in the player or something that needs to be reset on my server?
I'm running Chrome version 57.0.2987.133, running on Windows 7, with Plex version 18.104.22.16880 running on an Ubuntu 16.04 server. The problem has persisted through the last two Plex upgrades.