I have a number of Ubiquiti radios as bridged units and TP-Link Routers in customers houses configured as PPPoE clients, the PPPoE server is on a RB2011 firmware 6.1 at the moment, has been 6.3 made no difference to this problem.
When I look at Active Connections I have noticed that the MAC addresses are not the MAC addresses of the TP-Link routers but the MAC addresses of the Ubiquiti radios, why?, they are not even configured for PPPoE