Weird buffering error when playing local movies

I recently upped to a RP4B. After getting my library sorted i find when I watch movies from my hard drive using the movies source, they buffer continuously. First I get the little wheel, then the circle with numbers. Like every ten seconds. But if I play them thru file manager, or thru videos from the directory, they work just fine. Also when I hit stop, often times the system gets stuck and I have to soft reboot. But not when I play from file manager or from videos. Anyone run across this?