Polycom 8800 Trio with Visual+ Box Meet Now Button going Straight into Lobby

I have setup a Polycom 8800 Trio with Visual+ Box. The Trio has the latest firmware and can join video and voice SfB calls fine. We have a hybrid deployment and the Exchange 2013 server is on-premise. The SfB account that the Polycom uses is a meeting room account and homed online in O365. It currently has an E3 license with SfB Online plan 2.

When I press the meet now button the Polycom is put straight into the lobby. I have had a look at the SfB Online policies and they seem to be ok. But this must be a policy configuration that is causing the issue, so can anyone share any information on which policies may cause this issue or has anyone seen this before and resolved the issue?