As described in: https://forums.plex.tv/t/live-tv-dvr-missing-the-device-is-in-in-use-with-existing-dvr/691158/6
Went into Databases subdirectory, backed up the directory, and the deleted all files that begin with tv.plex.providers.epg*
That appears to have deleted my DVR within Plex, but kept my DVR Schedule. I then easily re-added the DVR, and now it works (again). We’ll see how long that lasts…
