All I want Plex to do is serve some MP4 files from a raspberry pi. I had it working at one point with some hidden setting. But now it keeps trying to transcode

All I want Plex to do is serve some MP4 files from a raspberry pi. I had it working at one point with some hidden setting. But now it keeps trying to transcode and such. And it'll randomly just stop working and I have to reboot the pi. Looking for something simpler, something I can use to just Chromecast MP4 files without all of Plex bells and whistles that seen to make it fragile.