I have a segment of the network that is bridged. The client devices are setup as basic routers with a wlan1 (WAN) and ether1 (LAN) interface.
The pppoe-out interface is set to wlan1. Wlan1 is setup in station mode and basic NAT config settings.
AP is setup as a straight bridge, ap-bridge mode, bridge-mode=enabled, and the AP interface and other necessary interfaces are added to the bridge.
For some reason the AP isn't learning all the connected MACs in the bridge table and thus those that aren't learned cannot pass traffic and cannot connect via PPPoE. Some can however, and those that can don't have any different configuration than those that can't it's very arbitrary.
This problem seems to be related to a recent upgrade to RouterOS v5.5 but I'm not 100% sure.
It's very odd.. I'm going to try downgrading to an earlier 5.x release to see if the problem goes away. Any comments, suggestions appreciated because I've tried most everything that makes logical sense.