I get this glitch every now and again, happened frequently in 3.251, but not seen it yet in 3.260
given the following folders where all alpha shows are pre-existing and all numeric are newly added.
show a\season 01\show.a.s01e01.episode.1.avi
show added 1\season 01\show.1.s01e01.episode.1.avi
show b\season 01\show.b.s01e01.episode.1.avi
show added 2\season 01\show.added.2.s01e01.episode.1.avi
show added 3\season 02\show.added.3.s03se05.episode.5.avi
show c\season 01\show.c.s01e01.episode.1.avi
after "TV Shows| Check Roots for new tv shows", the fanart in each of the scraped folders will be identical to the first scraped show.
md5sum "*\fanart.jpg" | sort
4e3a6cea570b3fef133fb99446852dca *show added 1\fanart.jpg
4e3a6cea570b3fef133fb99446852dca *show added 2\fanart.jpg
4e3a6cea570b3fef133fb99446852dca *show added 3\fanart.jpg