Balance 305 config WAN2 issues

HI All
I have a balance 305 with WAN1 configered in Dropin mode and working on my SBS domain
but I am unable to get WAN2 configered with out getting the Public DNS error
WAN2 port config : A.A.A.9 router with static IP is A.A.A.8 Gateway is A.A.A.8 I have tried DNS of A.A.A.8 and A.A.A.9 all with errors.
I have even tried the LAN IP of 305 which still gives me error,
PS: for got to mention that WAN1 is on different subnet to WAN2

what am I missing ?
thank you in advance

Try using Google and for public DNS on WAN 2. Does that work?

thank you Ron WAN2 now working
I’m sure I willhave more questions