Since yesterday, I don't seem to get any credit for joining a team from the kiosk. I have tried it with both my characters. I think it is bugged. Please check into this.
I just went in and tested this and was able to get credit for helping out on the team kiosk. I wonder if there is some more details you can give to try to track it down.
I still have this problem with both characters. I did notice something strange when I go to the join a team kiosk. When I click on the "join a team" the skeleton key teams show up first. I used to see all the worlds at the top so this was a change. Basically this started happening about 4-5 days or so ago after a patch.