Thanks @svanheule, upgrading my EAP225-Outdoor from stock 1.5.0 to 1.6.1 then to your late July build worked perfectly.
5G works great in access mode with WPA2 PSK (CCMP) and 802.11r Fast Transition enabled, awesome!
Cannot make 2G work in access mode though, interface stays disabled, not sure why yet.
FWIW, I followed these instructions from another thread: