[Karellen]

You are right, there is no mention of Grey's Anatomy, nor any other TV Show in that log. Are your Sources correctly setup? If we cannot see Sources in log, means Kodi cannot see them.

This all works great, except that some shows sometimes don't get picked up. 

Some shows? There are no valid shows in the log, just non-existent ones. Maybe you have the path set up incorrectly.