issues with Netpath

We have Netpath setup to monitor the external DNS servers (port 53) we use

Since this morning one of the Netpaths is reporting no connection to host from any pollers, but we can do nslookup from those servers and ping
The other external DNS servers are fine from the same polling engines with the same netpath setup

I have restarted the relevant services and even an entire poller but still no improvement

Any advice or do I need to talk to support?