Club joining flaw?

Hello! Whenever I try to invite someone to a club, they don't receive the invite right away. Sometimes it takes 2-3 minutes, sometimes 20, sometimes the invite never goes through.

Now, when I finally invite someone and they message me saying "I'm in", it shows "2 members online" on my screen, and their screen shows that they are in the club, but it still says "pending" for the user. Do I need to wait till it updates?

Thank you!