Workaround for mt76: https://github.com/openwrt/mt76/issues/922

openwrt-mt76-disconnect-workaround.startup

(
disconnect() {
  local dev=$1
  local mac=$2
  echo "$dev: disconnect $mac" > /dev/kmsg
  ubus call hostapd.$dev del_client "{'addr':'$mac', 'reason':8, 'deauth':true, 'ban_time':0}"
}

mt79_rssi_monitor() {
  local dev=$1
  echo "$dev: watchdog [rssi-monitor]" > /dev/kmsg
  (
    while true; do
      sleep 5
      stas=$(iw dev "$dev" station dump | awk 'BEGIN {RS="Station"; ORS="\n"} {gsub(/\n\s/, " "); print $0}')
      noise=$(iwinfo "$dev" info | grep -oE 'Noise:\s(-?[0-9]+)' | awk '{print $2}')
      echo "${stas}" | while IFS= read -r sta; do
        if [ -z "$sta" ]; then continue ;fi
        mac=$(echo "${sta}" | grep -oE '([a-f0-9]{2}:){5}[a-f0-9]{2}')
        signal=$(echo "${sta}" | grep -oE 'signal:\s*(-?[0-9]+)' | head -n1 | awk '{print $2}')
        sensed=$(echo "${sta}" | grep -oE 'inactive time:\s*([0-9]+)' | awk '{print $3}')
        if [ "$signal" -lt "$noise" ] &&
           [ "$sensed" -gt 10000 ] ||
           [ "$sensed" -gt 20000 ]; then
          disconnect "$dev" "$mac"
        fi
      done
    done
  ) &
}

# Ensure necessary services are up
sleep 40

# Start bogus-client monitoring for APs
for dev in $(iwinfo | awk '/phy[0-9]-ap[0-9]/ { print $1 }'); do
  mt79_rssi_monitor "$dev" &
done
)

If this is working you should see something like this:

[   37.914315] phy0-ap0: watchdog [rssi-monitor]
[   37.914350] phy1-ap0: watchdog [rssi-monitor]

With events following:

[  171.348035] phy0-ap0: disconnect 70:22:FE:9D:3E:E0