Dear alzhao,

I have found reasons for my problems with TOR gateway on openwrt-mt300a-tor-1.4.bin
Trouble came from second DHCP server in the same LAN segment as TOR gateway.
Apparently, this foreign DHCP traffic went through LAN-WLAN bridge and changed settings of WiFi-connected client.
After disabling that second DHCP server, TOR gateway works as expected.
Sorry for troubling you with this problem, and thanks for the great work!!!