Seasons 6 and 7 were split into two halves for airing. This led to some sources claiming that each half was a separate series.
The same problem happened with the first four seasons (the OG ones). They were split up and episodes were aired out of order, so some sources claim that there are five seasons. It's really, really annoying if you want to watch the episodes in order and Plex has decided that "fuck you no, there are five seasons of random lengths" >_<