Netflix and movies series

[AintNobodyHereButUsChickens]

Why do Netflix only have part of a series of movies on? Jeepers Creepers 3 popped up and I thought I'd save it to my list and then go and look for the first two to watch, 1 and 2 are not on there. Same with the Scary Movie series, they have 1, 2, 3 and 5, but no 4 . They have Fifty Shades Darker, but not Fifty Shades of Grey or Fifty Shades Freed (not that I'm so bothered about these it's just that I keep seeing FS Darker pop up but never the other two!).

Anyone know why this is? It's so random!

[AintNobodyHereButUsChickens]

There's also Ted, but not Ted 2