health check failing for IPv6 DNS type monitor

Hello all, I'm working on a issue where health check is failing on LB for IPv6 type DNS type monitor.

 

I did a packet capture LB and I'm finding the successful query and response will before the timeout interval and for some reason LB is considering the node is down with the log message "UDP recv: connection refused; No successful responses received before deadline"

 

If i'm removing and adding the monitor then the status of the node is comming up and after a day the node is going down.

 

Could you please advice me on resolving the issue?

 

Any best practices to be followed for IP v6 DNS type monitor?

 

Regards, Thiyagu