I am having similar issues attempting to record shows. I have a lifetime plexpass. I’m using HD Homerun Tuner with Plex x9200 running on a Windows 10 machine i5/8400 cpu using built in video. I have several shows that I’m using Plex to record, and I found that the recording ends abruptly between 12-20 minutes into the show. I have reverted to x8921; we’ll see if that helps. Like others reporting difficulties in this thread, I’m mostly using ROKU for playback. I can verify through the HD Homerun App that the HD Homerun is working and picking up the shows. But when I look at the recorded shows on the PC they are truncated, and when I look at the files directly through windows explorer, the smaller file size is consistent with the reported recording time.
