I'll try to add them

Oh it looks like the seasons are locked, and on roosterteeth.com Zero and Family Shatters don't have consecutive season numbers. If anyone has more knowledge on the series, please determine if they should be added as more seasons or new show entries on TMDB.

Zero was an attempt to change up the show that was ultimately unsuccessful but is considered canonical and will not be ignored by future series but they will be moving away from the characters set up in the season, my reading of this is that its still season 18 thy just wont be continuing the story in season 19 making it an experimental season like 14. https://twitter.com/seanhinz/status/1509229023771205645?s=21&t=ysp5ydVVsMXiOTHX8BVsGw

however Family Shatters is a non canonical sequal to zero so would fall more into the same catagory as a PSA imo

Okay I don’t quite follow, but it seems nonstandard if they don’t call it “season 18”. If you don’t want to wait for this entry’s seasons to get unlocked you can create a new tv show from the options at the footer of the TMDB website, and add the spin-offs separately.

As you can see here on the official YouTube channel the complete version of zero is labeled as season 18: https://youtu.be/wd6c0srEZSA

Okay so that means they aren’t going to make a different thing called “season 18”, I think that counts then. If they add Family Shatters Complete as season 19 we’ll know that too. @moderator please unlock it