[dns-operations] dnsviz.net complaining "UDP_-_NOEDNS_" for gtld-servers.net

[Thomas Mieslinger]

I have a customer complaining being unable to send/receive email.

https://dnsviz.net/d/sportsproducts.net/dnssec/

shows errors:
     sportsproducts.net/DS: No response was received from the server
over UDP (tried 12 times). (2001:502:1ca1::30, 2001:503:d414::30,
2001:503:eea3::30, UDP_-_NOEDNS_)

     sportsproducts.net/NS: No response was received from the server
over UDP (tried 12 times). (2001:502:1ca1::30, 2001:503:d414::30,
2001:503:eea3::30, UDP_-_NOEDNS_)

 From Germany (more specific HE-FRA) I can not reproduce this error.

 From us-mkc (as8560): no problem.

Answer size reported by dig: 864 (ds)/ 643 (ns)

Anyone an idea what is wrong?

Cheers

Thomas