Life Below Zero (TV Series 2013- ) — The Movie Database (TMDB) <— it’s in your list, except the current season is 19, and 6 episodes have aired. Your app is still only showing season 1 -18.
Clicking your link to TMDB shows that they only have 18 seasons listed which would be correct as Series Guide uses TMDB.
It does have season 19 on TVDB so season 19 needs adding to TMDB for it to show up on SG.