health monitor dns timeout

I have a Virtual Server for my 2 DNS platforms

 

My virtual server has 1 pool with 2 members

 

My Pool has a health monitor, tcp, udp, and a DNS lookup

 

TCP is set to 1 second interval 4 second timeout

 

UDP is set to 1 second interval 4 second timeout

 

DNS lookup to 5 second interval, 16 second timeout

 

 

My problem is the monitor is constantly triggered , so i then log directly into my DNS and check to see if there are concerns, i get milliseconds response when performing a dig command.

 

 

I am puzzled, any thought would be appreciated