FG60D, 2 WAN in transparent mode

[jonbong]

Hi All

i just took over from a colleague who has left the company and i have the following issue

SWITCH 1 --> FG60D (wan1) -->Router 1 (172.27.16.2)

SWITCH 1 --> FG60D (wan2) -->Router 2 (172.27.16.3)

gateway (172.27.16.1)

in transparent mode

it was working previously but 1 month ago, we are unable to connect to other sites which previously can,

If we remove 1 wan, all will be normal

if both routers are plug to the switch, it will work fine as well

I have tried to set the priority but same issue.

i noticed the traffic to be LAN to external via WAN1 and External to LAN via WAN2.

Any suggestion to fix this issue?