Some attendees still have to wait in lobby when option 'nobody has to wait in the lobby' is selected

Hi,

Does someone have a solution for us? As title says some attendees still have to wait in the lobby when the option 'nobody has to wait in the lobby' is selected for the meeting. We can accept them so they can join just fine after that, but it should not be necessary. Nobody can 'call in' so this option is greyed out. 

We don't use any custom policies. The default ones are fine for us.