Inbound Automous System IP hosted service inaccessible over secondary WAN link

We have the Peplink Balance 2500 setup as follows

         <img src="//discourse-cloud-file-uploads.s3.dualstack.us-west-2.amazonaws.com/business5/uploads/peplink/original/1X/d96a92c8b2226051abd8b18095ff4a71e366d363.PNG" width="690" height="321"><br/>

Traffic inbound to our AS e.g 192.0.2.0/24 ( through interface WAN1 ) for hosts natted directly on the firewall is fine.

However, traffic inbound on the WAN2 interface isn’t reaching the firewall.

I see we have responded with ticket 751560 and we can use that if there are additional questions on this design.