Yours appears to be the first reported at least having that particular issue.
I think I would shut it all down, unplug the Power Inserter, unplug the recvr, wait a few minutes then plug in the PI. let it boot up and then plug in the recvr and let it go thru its boot up process .... theres really not that many things in that particular set up ... the dish/LNB, coax, PI, recvr, HDMI and TV.
Also, just thinking about this here, of late, some are asking why the recvr has decided to run all showings of an episode back to back and don't like it because it does it like that ... your is just the opposite.
Now when I am watching a recording, once the recording it over, I FF to the end and go on to whatever show or channel I want next ... however, if you just let it pal to the end, it will say do you want to delete ... I typically make that choice and move on, but if I don't ... I'm wondering if it waits a certain amount of time and then goes back to the channel your on, which would make sense to me.