On testing the more than 1 player in Solo type instance, I have found a 'bug', if you have max players set to 2, and 2 players join the instance, it correctly locks anyone else from entering.
If one of those players leaves, it allows a new player to join (again that seems correct)
if that previous player tries to join, they are still allowed to join even when it's full. (I assume that's a conditional check that's missing, but I can't work it out)
On testing the more than 1 player in Solo type instance, I have found a 'bug', if you have max players set to 2, and 2 players join the instance, it correctly locks anyone else from entering. If one of those players leaves, it allows a new player to join (again that seems correct) if that previous player tries to join, they are still allowed to join even when it's full. (I assume that's a conditional check that's missing, but I can't work it out)