For some reason my OQ was working like it is supposed to, but after a while (without an update or anything) it started to drop me from the group at the same time I get in it, any suggestions?

If you are running elvui or another addon which auto accepts group invitations you need to disable that feature in that addon. When two addon both try to auto accept the same group invitation, addon A will accept the group invitation, then addon B tries to accept the same invitation, but it has already been accepted, so what it does is it kicks you from the group.

Thank you, that did solve it!