Why did I get a partial recording?

Last night (4/8) I tried to record most of the Fox shows. For some reason my recording of “The Simpsons - E15 - No Good Read Goes Unpunished” was terminated at 8:15. It was scheduled to record from 7:59 - 8:31 eastern. The other shows in the line-up were recorded without error. Can someone please explain why? I see “Plex Media Server.4.log” noting bogus completion at 20:15, but why? And, more importantly, what can I do to prevent this from happening again?
thanks in advance, logs attached…