Wireless Client Mode no Internet

I'm trying to setup WAN failover to Wireless Client Mode.

  1. WAN has normal Internet in PPPoe.
  2. Wireless Client Mode connect, wwan interface (wlan0 device) has the IP in DHCP mode. Firewall is assigned to wan.
  3. Trying to "ping -c 4 -I wlan0" -> 100% lost.
  4. Trying to "traceroute -i wlan0" -> route only go DHCP IP of wireless client with over 3000ms and drops.

WCM setting:

config wifi-iface 'wifinet4'
	option device 'radio0'
	option mode 'sta'
	option network 'wwan'
	option ssid 'name ssid'
	option key 'pass'
	option encryption 'psk-mixed'

What have I tried to workaround:

  1. Tested with my another openwrt router and it could access normally with same wifi.
  2. Turn off firewall
  3. Recreated connection of Wireless Client Mode and delete all other wifis on the same radio.

Anyone could suggest me where to check more?

Did you setup mwan?

Yes. Mwan3 has been set up
But WWAN doesn't have Internet. I want to know where to check with WWAN internet 1st.

I'd suggest setting this to the actual config of the AP (or the highest security if it is set to mixed).

All the setting of Client mode are the same as actual config of source wifi.
I have tested the same as my another router and it works.