@lestaff Can someone maybe look into the traffic or detailed logs on the resolvers?
This is the ~5th time in the last week or so that someone has reported issues under similar circumstances (half of them were with one DNS service, Gransy): Very large responses (because of large DNSSEC signatures and/or non-minimal responses), sometimes CNAME records, TCP.
"No valid IP addresses found" seems particularly strange -- a SERVFAIL or "query timed out" error would be unfortunate but logical if there were resolution issues; "No valid IP addresses" doesn't make sense when the records apparently do exist.
Past threads include: