Kia Ora,
Just rolled a 21.02 today for WRT190ACS. Everything is default for the model except I added the advanced reboot pkg
Using LuCI I have created a second interface assigned to lan2 (tamariki), which works fine. However when I try to bridge the wlan0 (kids wifi) connection to lan2 the lan2 interface gets disabled - port light in router goes out. wlan0 works fine.
Looking at /etc/config/network & ./wireless all looks OK however when I run "brctl show" lan2 is absent from the bridge br-tamariki
root@OpenWrt:~# brctl show
bridge name bridge id STP enabled interfaces
br-lan 7fff.<hidden> no lan3
lan1
br-tamariki 7fff.<hidden> no wlan0
If I bridge wlan0 to br-lan, then all interfaces appear
root@OpenWrt:~# brctl show
bridge name bridge id STP enabled interfaces
br-lan 7fff.<hidden> no wlan0
lan3
lan1
How do I get br-tamariki to bridge lan2 and wlan0? I cannot seem to see a config file for this.
Here is my ./network
config interface 'loopback'
option ifname 'lo'
option proto 'static'
option ipaddr '127.0.0.1'
option netmask '255.0.0.0'
config globals 'globals'
option ula_prefix 'fddb:782a:c615::/48'
config interface 'lan'
option type 'bridge'
option proto 'static'
option ipaddr '192.168.1.1'
option netmask '255.255.255.0'
option ip6assign '60'
option ifname 'lan1 lan3'
config interface 'wan'
option proto 'dhcp'
option ifname 'wan.10'
config device 'wan_wan_dev'
option name 'wan'
option macaddr '<hidden>'
config interface 'wan6'
option proto 'dhcpv6'
option auto '0'
option ifname 'wan.10'
option reqaddress 'none'
option reqprefix 'auto'
config interface 'tamariki'
option proto 'static'
option ifname 'lan2'
option ipaddr '192.168.3.1'
option netmask '255.255.255.0'
and here is my ./wireless (just in case 
) where wlan0 is bridged lan2
config wifi-device 'radio0'
option type 'mac80211'
option channel '36'
option hwmode '11a'
option path 'soc/soc:pcie/pci0000:00/0000:00:01.0/0000:01:00.0'
option htmode 'VHT80'
option country 'AU'
option cell_density '0'
config wifi-iface 'default_radio0'
option device 'radio0'
option mode 'ap'
option macaddr '<hidden>'
option ssid 'Bunny_Tamariki'
option encryption 'psk2+ccmp'
option key '***'
option wpa_disable_eapol_key_retries '1'
option network 'tamariki'
config wifi-device 'radio1'
option type 'mac80211'
option channel '11'
option hwmode '11g'
option path 'soc/soc:pcie/pci0000:00/0000:00:02.0/0000:02:00.0'
option htmode 'HT20'
option disabled '1'
option country 'AU'
config wifi-iface 'default_radio1'
option device 'radio1'
option mode 'ap'
option ssid 'OpenWrt'
option encryption 'none'
option macaddr '<hidden>'