nl/DS (alg 13, id 17153): No response was received from the server over UDP (tried 6 times) until the COOKIE EDNS option was removed (however, this server appeared to respond legitimately to other queries with the COOKIE EDNS option present). See RFC 6891, Sec. 6.1.2. (192.33.4.12, UDP_-_EDNS0_4096_D_KN)
nl/DS (alg 13, id 17153): No response was received from the server over UDP (tried 6 times) until the COOKIE EDNS option was removed (however, this server appeared to respond legitimately to other queries with the COOKIE EDNS option present). See RFC 6891, Sec. 6.1.2. (192.33.4.12, UDP_-_EDNS0_4096_D_KN)
nl/DS has warnings; select the "Denial of existence" DNSSEC option to see them.