bridging the 2nd wan to local

hi support

i have a setup before in balance 380 we have two different appliance under peplink via dropin-mode in wan/lan bypass and it working fine but last night the power supply of balance 380 malfunction so i decided to replace a temporary in balance one core model but the 2nd wan bridging to 2nd lan is not working or maybe i missed did something wrong with the configuration? need to bridge the wan2 to lan2 in order to use a public IP in my office router. the only purpose of peplink intended as a load balancer
please help