Can't group up in the underground

[Dyna_glide]

My friend and I can't join or invite each other as soon as we go down into the underground.  Both of us have completed the tutorial and it still won't let us.  If anyone has any ideas on how to solve this problem please let me know.

 

[Oh. daesu]

My friend and I can't join or invite each other as soon as we go down into the underground.  Both of us have completed the tutorial and it still won't let us.  If anyone has any ideas on how to solve this problem please let me know.

You'll need to matchmake down in the underground station, at the desk. screenshot below.

As for invites, maybe try both going down to the underground station and then invite from there, than trying it topside and then going down.