Actually, it's possible it isn't a bug. Or maybe it is. Please relocate appropriately. ;D
Membergroups requiring request and approval do not provide a notification to the appropriate forum personnel for approval. The request shows in the Moderation panel, but there is nothing to prompt the visit. On the flip side, the member is not notified of the decision either, including a rejection reason if appropriate.
Full disclosure: the forums are using modified themes. The modifications are css only. This is pertinent in the event the modded css is somehow missing something critical.
Powers that be, feel free to tell me I'm a dummy, if applicable. ;) Thanks guys, hope you're having a great weekend!
I'm going to mark this unread and get back to it as soon as I can .... have to set things up the same way so I can fully understand the problems. The css only theme should not matter one bit.