Can’t provision/adopt Unifi with Mikrotik bridge

Anyone found that they can't provision or adopt a Unifi AP through certain equipment? I've tried setting a little mikrotik as a plain switch with all ports bridged. The Unifi controller setup detects the AP when assigning passwords and the SSID but initially fails the provisioning then fails the adoption

The SSID does get set and otherwise works. Swapping in a switch and near instantly everything is fine.