@JeffCrum You are correct Plex doesn’t check the tuner. It assumes if you configured the device/tuner in Plex DVR then you obviously intended for it has exclusive access to the tuners. Since it assumes it has exclusive access it checks to see what tuners configured are available and uses one that is free in the Plex pool of tuners. If you are using that particular tuner in some other application outside of Plex the tuner will not respond to the request from Plex and your recording will fail.
Hopefully in the future they will add logic to query tuners perhaps 30 seconds before the show start time, including any before minutes we establish for the recording, to determine if it is available. If it is then it will start the recording using that tuner at the appropriate start time, if not it could then check for the next tuner until an available tuner is found or all tuners have been checked.
