Hello, I am having difficulty view any live TV on my Apple TV or any devise except from the Plex website and logging in, however this is very slow. I have a Plex pass and a HD Homerun. HomeRun is programmed and working standalone (LAN only)
We need to know more about the hardware that the Plex Media Server is installed on:
Be aware that if you run your Plex Media Server on a low-powered NAS device that doesn’t support transcoding, many apps will be unable to play recorded content. Over the air broadcasts are often in MPEG2 or other older formats, which few devices or apps can play directly (and would thus require transcoding in those cases).
(from: https://support.plex.tv/articles/226463767-frequently-asked-questions-dvr-live-tv/ under What version of Plex Media Server is required?).
Also, you might get better results with an HDHomeRun Extend which does transcoding on the fly.