Hello @ducttapebeiler
you can take a look here: https://forums.plex.tv/t/what-other-support-is-there-when-the-forum-doesnt-deliver/512490/18
I have similar setup, but I use tvheadend + tvhproxy + pms
Plex clients often does not support transcoding of livetv and the rpi4 is not strong enough to do it in real time, indeed I have a Pi4 with a tvhat running a snap of tvheadend that have much better client support (i.e. LibreELEC on another Pi) and a ryzen 5 with ubuntu 20.04 running pms and tvhproxy that share the tv to plex.
Good luck!