Along with what scottygelb said, make sure your DNS servers allow standard A queries over port 53 to example.YOURDOMAIN.COM and that port 53 is open between the cluster LIF and DNS server.
"dns check" is used when you configure DNS.
TR-4835 details the dns check command on page 104:
https://www.netapp.com/us/media/tr-4835.pdf
You can also try the -skip-validation true option, which skips DNS check and then test name service lookups with the example on page 34 of the same TR.