MT7621 - Clients disconnecting

Wed Aug  5 13:20:29 2020 daemon.notice hostapd: wlan0: AP-STA-CONNECTED 90:78:****
Wed Aug  5 13:20:29 2020 daemon.info hostapd: wlan0: STA 90:78:**** RADIUS: starting accounting session ACBA497F6AD16C46
Wed Aug  5 13:20:29 2020 daemon.info hostapd: wlan0: STA 90:78:**** WPA: pairwise key handshake completed (RSN)
Wed Aug  5 13:20:29 2020 daemon.info hostapd: wlan1: STA 90:78:**** IEEE 802.11: deauthenticated due to inactivity (timer DEAUTH/REMOVE)
Wed Aug  5 13:20:35 2020 daemon.notice hostapd: wlan0: AP-STA-DISCONNECTED 90:78:****
Wed Aug  5 13:20:35 2020 daemon.info hostapd: wlan0: STA 90:78:**** IEEE 802.11: disassociated
Wed Aug  5 13:20:35 2020 daemon.notice hostapd: wlan1: STA-OPMODE-N_SS-CHANGED 90:78:**** 1
Wed Aug  5 13:20:35 2020 daemon.info hostapd: wlan1: STA 90:78:**** IEEE 802.11: associated (aid 1)
Wed Aug  5 13:20:35 2020 daemon.notice hostapd: wlan1: AP-STA-CONNECTED 90:78:****
Wed Aug  5 13:20:35 2020 daemon.info hostapd: wlan1: STA 90:78:**** RADIUS: starting accounting session B30F2D4C310A41EA
Wed Aug  5 13:20:35 2020 daemon.info hostapd: wlan1: STA 90:78:**** WPA: pairwise key handshake completed (RSN)
Wed Aug  5 13:20:36 2020 daemon.info hostapd: wlan0: STA 90:78:**** IEEE 802.11: deauthenticated due to inactivity (timer DEAUTH/REMOVE)

Model	Netgear R6220
Architecture	MediaTek MT7621
OpenWrt 19.07.3 r11063-85e04e9f46 

config wifi-device 'radio0'
	option type 'mac80211'
	option hwmode '11g'
	option path 'pci0000:00/0000:00:01.0/0000:02:00.0'
	option htmode 'HT20'
	option country 'PL'
	option channel '11'
	option legacy_rates '0'

config wifi-iface 'default_radio0'
	option device 'radio0'
	option network 'lan'
	option mode 'ap'
	option ssid '*****'
	option key '**********'
	option ft_over_ds '1'
	option ieee80211w '1'
	option ft_psk_generate_local '1'
	option ieee80211r '1'
	option mobility_domain '27DB'
	option encryption 'sae'
	option disassoc_low_ack '0'

config wifi-device 'radio1'
	option type 'mac80211'
	option hwmode '11a'
	option path 'pci0000:00/0000:00:00.0/0000:01:00.0'
	option htmode 'VHT80'
	option country 'PL'
	option channel '128'
	option legacy_rates '0'

config wifi-iface 'wifinet3'
	option ssid '*****-IoT'
	option encryption 'psk2+ccmp'
	option device 'radio0'
	option mode 'ap'
	option ieee80211w '1'
	option key '**********'
	option ft_over_ds '1'
	option ft_psk_generate_local '1'
	option ieee80211r '1'
	option mobility_domain '285D'
	option disassoc_low_ack '0'

config wifi-iface 'wifinet4'
	option ssid '*****_5GHz'
	option device 'radio1'
	option ieee80211r '1'
	option ft_over_ds '1'
	option key '**********'
	option network 'lan'
	option mode 'ap'
	option ieee80211w '1'
	option ft_psk_generate_local '1'
	option mobility_domain '27DB'
	option encryption 'sae'
	option disassoc_low_ack '0'

config wifi-iface 'wifinet6'
	option ssid '*****_5GHz-IoT'
	option encryption 'psk2+ccmp'
	option device 'radio1'
	option ieee80211r '1'
	option ft_over_ds '1'
	option key '**********'
	option mode 'ap'
	option ieee80211w '1'
	option ft_psk_generate_local '1'
	option mobility_domain '285D'
	option disassoc_low_ack '0'

config wifi-iface 'wifinet5'
	option ssid '*****-Guest'
	option encryption 'psk2+ccmp'
	option device 'radio0'
	option mode 'ap'
	option ieee80211w '1'
	option ft_over_ds '1'
	option mobility_domain '28B1'
	option ft_psk_generate_local '1'
	option ieee80211r '1'
	option network 'lan'
	option key '**********'
	option disassoc_low_ack '0'

config wifi-iface 'wifinet7'
	option ssid '*****_5GHz-Guest'
	option encryption 'psk2+ccmp'
	option device 'radio1'
	option mode 'ap'
	option ieee80211w '1'
	option ft_over_ds '1'
	option ft_psk_generate_local '1'
	option ieee80211r '1'
	option mobility_domain '28B1'
	option network 'lan'
	option key '**********'
	option disassoc_low_ack '0'

Start with the supplied hostapd disconnect logs and the Netgear R6220 MT7621 wireless configuration. Compare behavior across the radio and interface settings shown, then identify a reproducible disconnect scenario and the relevant driver behavior. Done means clients remain connected under the reported configuration without the logged deauthentication and reassociation cycle.