which configuration are you referring to? if it's V4 please provide ip route print output
plus config again because v4 should work
You can force any DNS request to use your DNS by using dst-natthese are not needed as dns is on another network
SAME configuration in other RB is working 100%
comment=inside to outside route mark WAN1 chain=output action=mark-routing new-routing-mark=to_ISP1 passthrough=no connection-mark=WAN1_conn log=no log-prefix=""