I have two Openwrt devices in WDS AP-Client mode over 5GHz radios, but the 2.4GHz radios are set up on non-overlapping channels as independent APs sharing the same SSID with 802.11r enabled. The roaming worked well for a while, according to an Android phone in Developer mode (which shows the rssi, score, etc. of both channels under the same SSID).
However, now Android has put the the SSID in disabled state due to NETWORK_SELECTION_DISABLED_ASSOCIATION_REJECTION. Forcing the selection of the SSD results in "Access point temporarily full" and NETWORK_SELECTION_DISABLED_ASSOCIATION_REJECTION=4. Suffice to say there aren't that more than 8-9 devices overall on my LAN.
What could have caused this (did I roam too often between two in my testing, filling some buffer?) and how do I troubleshoot/resolve it?