ip6.arpa/DNSKEY (alg 8, id 21619): No response was received until the UDP payload size was decreased, indicating that the server might be attempting to send a payload that exceeds the path maximum transmission unit (PMTU) size. See RFC 6891, Sec. 6.2.6. (193.0.9.2, UDP_-_EDNS0_4096_D_KN)
ip6.arpa/DNSKEY (alg 8, id 40105): No response was received until the UDP payload size was decreased, indicating that the server might be attempting to send a payload that exceeds the path maximum transmission unit (PMTU) size. See RFC 6891, Sec. 6.2.6. (193.0.9.2, UDP_-_EDNS0_4096_D_KN)
ip6.arpa/DNSKEY (alg 8, id 64060): No response was received until the UDP payload size was decreased, indicating that the server might be attempting to send a payload that exceeds the path maximum transmission unit (PMTU) size. See RFC 6891, Sec. 6.2.6. (193.0.9.2, UDP_-_EDNS0_4096_D_KN)
ip6.arpa/DNSKEY has warnings; select the "Denial of existence" DNSSEC option to see them.