[SB] /is join Bug

Your username: ewon1210
In which minigame/server does the bug occur: Skyblock
Detailed description of bug: Today i was looking for a island to join on skyblock 3 and i found out that you now have to do /is join when someone invites you to an island. So my friend invited me to the island and it said, 'zelyses wants to add you to party. If you agree use /island join if you want to accept his request'
So then i did /island join
And the message came up, 'You don't have permission to use that command.'
And then a second later, 'You did not respond to zelyses's request. Request removed.'
So then i couldn't join his island.
Pls fix this so that i can be on an island. Thank you!!

-ewon1210

EDIT:
Here are some screenshots




And BTW i am not part of another island.

 

I was about to report this too xD So instead i'll post my pictures here:

 

Thank you, this has happened to others as well, i see them complaining in the chat. Please fix this soon.

Ewon