Okay so i ahve my server hosted and up, I get arround 16 players when it says the server is full when anyone tries to join (its set on max players 32)
Any idea how do make it allow more people to join it

I don't know what's the error here,but the maxplayers is actually 16. I think only splitscreeners could join and then it would be 18. I am not really sure...but it's for everyone,not just for you. Buggy JJ2.

You can get 32 players but only 16 connections

Does that mean that you can join as a triplescreener when there are 15 people?

yes

Couldn't you change the max players VIA jj2+? I mean, it is host sided, and not the server list sided. right?

it'd take a lot of work to add extra connections