Haha yeah it gave me enough info to where to look.
It was essentialy this.
var postcount = parseInt("1,000", 10) + 1; which results in 2 instead of 1001 😆
This feature does not seam to work in 1.18.0.
The Group posts does not change if i set a category id.
edit: This does not work in groups in community.nodebb.org. Dont know what version in run here!
I believe this setting only effects new posts made. So once the setting is changed only new posts form those categories will be visible in the group page. But if there are old posts from other categories they will remain visible until more new posts are made by group members.
Ahh, ok! Will check that out!