I noticed that over the past couple of updates that I have one channel that fails to record. Have no problem watching the channel thru Plex via any web-browser (remotely or on the computer) or the android app. Some searching shows that other people used to have a similar issue a couple years back and it was fixed… below is the portion of the log that seems to pertain to my issue.
I tried doing a fresh install of Plex on a fresh install of Ubuntu but had the same problem. Unplugged my tuner (power and coax) for a while and now everything is back to working properly.