Excessive Wifi connect/disconnect log messages on C7 with v18.06 from some devices

Installing and Using OpenWrt Network and Wireless Configuration
21

I didn't even knew RADIUS were being used here, in a simple wpa2, home setup. I figured it out by debugging hostapd logs, when i seemed some logs like these around the wifi being disconnected:

Jan 14 16:37:28 turris hostapd: wlan0: AP-STA-CONNECTED a8:9c:xx:xx:xx:xx
Jan 14 16:37:28 turris hostapd: wlan0: STA a8:9c:xx:xx:xx:xx RADIUS: starting accounting session 994985A0332EDC6B
Jan 14 16:37:28 turris hostapd: wlan0: STA a8:9c:xx:xx:xx:xx WPA: pairwise key handshake completed (RSN)
Jan 14 16:37:30 turris hostapd: wlan0: AP-STA-DISCONNECTED a8:9c:xx:xx:xx:xx

I have done my wireless configuration as simples as possible to work with fast transition:

config wifi-device 'radio0'
	option type 'mac80211'
	option path 'soc/soc:pcie/pci0000:00/0000:00:02.0/0000:02:00.0'
	option band '5g'
	option hwmode '11a'
	option country 'TW'
	option cell_density '1'
	option htmode 'VHT80'
	option channel '149'

config wifi-iface 'default_radio0'
	option device 'radio0'
	option network 'lan'
	option mode 'ap'
	option ssid 'Lar Doce Lar'
	option key 'XX'
	option macfilter 'deny'
	list maclist '8C:5A:XX:XX:XX:XX'
	option ft_over_ds '0'
	option ft_psk_generate_local '1'
	option mobility_domain '123f'
	option ieee80211r '1'
	option dtim_period '3'
	option encryption 'psk2'

config wifi-device 'radio1'
	option type 'mac80211'
	option path 'soc/soc:pcie/pci0000:00/0000:00:01.0/0000:01:00.0'
	option band '2g'
	option channel '6'
	option country 'TW'
	option htmode 'HT40'
	option cell_density '1'
	option txpower '17'

config wifi-iface 'default_radio1'
	option device 'radio1'
	option network 'lan'
	option mode 'ap'
	option ssid 'Lar Doce Lar'
	option ieee80211r '1'
	option ft_over_ds '0'
	option key 'XX'
	option macfilter 'allow'
	option ft_psk_generate_local '1'
	option mobility_domain '123f'
	list maclist 'A8:9C:XX:XX:XX:XX'
	list maclist 'A8:9C:XX:XX:XX:XX'
	list maclist '34:23:XX:XX:XX:XX'
	option dtim_period '3'
	option encryption 'psk2'

So, I don't really know how to change this configurations to make it work again.
One last thing: changing cipher to CCMP, or disabling 802.11r does not prevent the disconnections to happen.