If a player is already inside a group non-registered on the dynamic group system, the player wont be able to create a new group (or the group is created then deleted since the player is not transferred). In order to fix that, the player must be putted inside a grpnull.

It is also possible that this issue only occurs when the leader of the initial group the player is in is AI.

Also since it is happening in a dedicated environment, the locality of the player and his group is different (player is remote and group local to the server)