I've started sharing my Plex library with a friend within the same city, but as soon as we start watching a movie at home, her stream starts buffering over at her place and is virtually unwatchable. I was under the impression that I could easily stream more than one movie at a time, even on a Pi. Is that not the case? What could be the limiting factor here? How would I find out where the bottleneck lies?
Setup: RPi 3 model B, Raspbian, PMS. All with latest updates. Connected through Ethernet port to our router with high speed internet (10mbps). All files are h.264 MP4 containers, there is no transcoding happening whatsoever. All media files are on a USB 2.0 drive connected directly to the Pi's USB port.