Please post full logs, Settinga/Server/Help, click the download logs link and upload the zip file created. Also include what show you are having a problem with, what time it should have started and when it should have ended.
Looks like you had some sort of network issue during the recording:
Dec 15, 2017 20:18:52.083 [13624] DEBUG - NetworkServiceBrowser: SSDP departed after not being seen for 21.501347 seconds: 192.168.1.1
Dec 15, 2017 20:18:52.083 [13624] DEBUG - NetworkServiceBrowser: SSDP departed after not being seen for 20.532630 seconds: 192.168.1.15
Dec 15, 2017 20:18:52.084 [13624] DEBUG - NetworkServiceBrowser: SSDP departed after not being seen for 21.902076 seconds: 192.168.1.22
Dec 15, 2017 20:19:02.087 [13624] DEBUG - NetworkServiceBrowser: SSDP departed after not being seen for 29.218037 seconds: 192.168.1.5
Dec 15, 2017 20:19:07.095 [13624] ERROR - DVR:Device: Error refreshing existing device device://tv.plex.grabbers.hdhomerun/10480E75, marking as dead.
Plex Server is reporting from what I can tell that possibly connection to your router (192.168.1.1?) disappeared, as well as connections to 192.168.1.15, 192.168.1.22, and your HDHR device (192.168.1.5). The Plex Transcoder then asked DVR to stop recording since it was no longer receiving any video/audio data:
Dec 15, 2017 20:19:07.650 [5948] DEBUG - DVR:Recorder: Asked to stop recording ‘Marvel’s Agents of S.H.I.E.L.D. - E4 - A Life Earned’.