Theirs a bug that's been around since the last rev update, and it's in regards to group leaders. When a group is formed, only the group leader gains the benefit of the leadership AA's. By this I mean, if the leader has health enhancement purchased, only he gets the benefit and no one else does.
When the group leader zones, he loses the ability to invite new members. It's as if when you first invite people, it triggers something that semi-recognizes you as a group leader..but once you zone then the group no longer has a leader. The only way to fix this is to have everyone disband, then reinvite everyone individually. Even then, you're still stuck with only the GL having the leader aa benefits.
Theirs also a bot bug where once a group zones, there can be issues with summoning bots/adding them to your group. The "group leader" will try to summon a bot and add it, but the bot will more often than not say that only the group leader can add bots to a group. This issue is long standing, and existed even before the group bug I speak of now.
To go more in detail about the bot bug, it works like this. Picture your group in pofire, and everyone but 1 of your group members zones out. If your leader zones back in, then he will still be recognized as being the group leader to bots, and can add bots freely. Now, if the whole group zones out and then back in, the group leader no longer exists in the bots eyes. If the leader attempts to add one, he will get the message that he's not the leader. If anyone else tries, they get the same message.
I'm not sure if the bot bug and the other group bug I stated at first are related, but if not then they're still tedious ><. I was hoping a rev update would fix it, but I haven't heard any news of another rev update so figured I'd finally just post this. I know I spoke with Striat in tells about it as soon as I noticed, but he wasn't really sure what the issue was off hand. I tried doing #grouprefresh on all toons, also, and it doesn't fix the issue.