Every time I want to continue a movie from a certain point, on my apple tv, it buffers forever to the point that I have to return to the the menu and try playing it at again. And some times I have to this procedure a couple of times before it starts playing. Sometimes I have to start from the beginning and just scroll to the part where I left off. WTF!!?? I never had this problem before. Also when selecting “Convert Automatically” in Settings under Quality it crashes the Plex Server entirely and I have to restart it again. WTF??!!
While not at all humorous; In the spirit of your question: “wtf?” is the server running on and what does the Media Info / XML show? Are you playing it with or without subtitles? 
We need to know more about your server and video being played to help you. Log files, captured right after recreating the problem are the most helpful (Settings - Server - Help - Download logs)
