unable to convert libuv error code in udp_send_cb to isc_result: -90: message too long

Version: 9.16.11-2~bpo10+1 (Debian Stable Backports) Kernel: 4.19.0-14-amd64 (Debian Stable)

These errors started appearing in syslog after the latest update to 9.16.11:

Feb  2 03:44:01 nsda named[634]: udp.c:595: unexpected error:
Feb  2 03:44:01 nsda named[634]: unable to convert libuv error code in udp_send_cb to isc_result: -90: message too long

My first thought was that it was being triggered by nefarious traffic, but several tests only showed normal DNS traffic.

Here is a tcpdump from that same time: (Note: 10.10.3.11/fd10:10:3::11 is the internal interfaces of the bind9 server nsda)

03:44:01.117113 IP 69.241.77.75.29944 > 10.10.3.11.53: 33501 [1au] A? d.ns.domainmail.org. (48)
03:44:01.117351 IP 10.10.3.11.53 > 69.241.77.75.29944: 33501*- 2/9/15 A 107.191.108.110, RRSIG (1357)
03:44:01.143210 IP 69.241.77.75.9974 > 10.10.3.11.53: 11710 [1au] A? b.ns.domainmail.org. (48)
03:44:01.143401 IP 10.10.3.11.53 > 69.241.77.75.9974: 11710*- 2/9/15 A 149.28.193.159, RRSIG (1357)
03:44:01.318600 IP 69.241.77.71.23952 > 10.10.3.11.53: 26903 [1au] A? a.ns.domainmail.org. (48)
03:44:01.318868 IP 10.10.3.11.53 > 69.241.77.71.23952: 26903*- 2/9/15 A 192.249.57.243, RRSIG (1357)
03:44:01.324725 IP 66.111.4.24.31115 > 10.10.3.11.53: 22388% [1au] A? b.ns.domainmail.org. (48)
03:44:01.324908 IP 10.10.3.11.53 > 66.111.4.24.31115: 22388*- 2/9/15 A 149.28.193.159, RRSIG (1357)
03:44:01.327499 IP 66.111.4.24.32637 > 10.10.3.11.53: 34737% [1au] A? d.ns.domainmail.org. (48)
03:44:01.327735 IP 10.10.3.11.53 > 66.111.4.24.32637: 34737*- 2/9/15 A 107.191.108.110, RRSIG (1357)
03:44:01.394857 IP 208.70.128.29.52101 > 10.10.3.11.53: 40050 [1au] TXT? ares._domainkey.domainmail.net. (59)
03:44:01.395092 IP 10.10.3.11.53 > 208.70.128.29.52101: 40050*- 1/8/9 TXT "v=DKIM1; h=sha256; k=rsa; s=email; " "p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwNWmypz1wHj9ctQtXDRdP5d7g8oUe6k0rGQ+ytNWSwelDqKVZYjYTpAJMTOv8fjW9EAuv0RMbnvht0Shsas0Hx2VFxA/UKg3FiJHn7STkzP7gEOUDg3BB6VmegE0AJlvEDF6IOxr/lqF59s3XmgABv8OykTkDb7hAPXf995wmda4slKlntKz/o+chaJsT7WEQk2HjDy9UVPvys" "yMvJfG6Fj7YdxhibgZcfcyomGA2FlNvpWVF4r/2FnBZT9VCYMMNKwYJd294rlwZIBiz1MYigJ3sqMEqUxp/ZTWXK8PidY/KrybkieEkB2pcK863kwniKpl5Nsh85weH1JiaU1rSwIDAQAB" (855)
03:44:01.471518 IP 69.241.77.85.50450 > 10.10.3.11.53: 29064 [1au] DNSKEY? domainmail.org. (43)
03:44:01.471678 IP 10.10.3.11.53 > 69.241.77.85.50450: 29064*- 2/0/1 DNSKEY, RRSIG (233)
03:44:01.560136 IP 20.186.78.216.50006 > 10.10.3.11.53: 59574 A? atlmm2.domainmail.NET. (39)
03:44:01.560341 IP 10.10.3.11.53 > 20.186.78.216.50006: 59574*- 1/8/8 A 192.249.57.242 (414)
03:44:01.571748 IP6 2603:10b0:514:8562:0:1:0:68.51100 > fd10:10:3::11.53: 53658 AAAA? atlmm2.domainmail.NET. (39)
03:44:01.571989 IP6 fd10:10:3::11.53 > 2603:10b0:514:8562:0:1:0:68.51100: 53658*- 1/8/8 AAAA 2604:180:0:6::242 (426)
03:44:01.608440 IP 76.96.47.197.37114 > 10.10.3.11.53: 16 [1au] TXT? _spf.domainmail.net. (48)
03:44:01.608452 IP 76.96.47.197.45007 > 10.10.3.11.53: 30758 [1au] A? a.ns.domainmail.net. (48)
03:44:01.608459 IP 76.96.47.197.64094 > 10.10.3.11.53: 38572 [1au] A? a.ns.domainmail.org. (48)
03:44:01.608748 IP 10.10.3.11.53 > 76.96.47.197.45007: 30758*- 2/9/15 A 192.249.57.244, RRSIG (1357)
03:44:01.608974 IP 10.10.3.11.53 > 76.96.47.197.64094: 38572*- 2/9/15 A 192.249.57.243, RRSIG (1357)
03:44:01.720424 IP6 2607:f8b0:4002:c11::108.40833 > fd10:10:3::11.53: 44325 [1au] AAAA? c.ns.domainmail.org. (59)
03:44:01.720637 IP6 fd10:10:3::11.53 > 2607:f8b0:4002:c11::108.40833: 44325*- 1/8/8 AAAA 2001:19f0:5001:3233::ca (392)
03:44:01.720854 IP6 2607:f8b0:4002:c02::10e.62330 > fd10:10:3::11.53: 51659 [1au] A? a.ns.domainmail.org. (59)
03:44:01.720964 IP6 fd10:10:3::11.53 > 2607:f8b0:4002:c02::10e.62330: 51659*- 1/8/8 A 192.249.57.243 (392)
03:44:01.781400 IP 104.208.223.97.63572 > 10.10.3.11.53: 54701 TXT? ares._domainkey.domainmail.NET. (48)
03:44:01.781639 IP 10.10.3.11.53 > 104.208.223.97.63572: 54701*-| 0/0/0 (48)
03:44:01.793719 IP 104.208.223.97.41874 > 10.10.3.11.53: Flags [S], seq 3112505391, win 64240, options [mss 1440,nop,wscale 8,nop,nop,sackOK], length 0
03:44:01.793769 IP 10.10.3.11.53 > 104.208.223.97.41874: Flags [S.], seq 1738835983, ack 3112505392, win 64240, options [mss 1460,nop,nop,sackOK,nop,wscale 7], length 0
03:44:01.804587 IP 104.208.223.97.41874 > 10.10.3.11.53: Flags [.], ack 1, win 2053, length 0
03:44:01.804752 IP 104.208.223.97.41874 > 10.10.3.11.53: Flags [P.], seq 1:51, ack 1, win 2053, length 50 54701 TXT? ares._domainkey.domainmail.NET. (48)
03:44:01.804807 IP 10.10.3.11.53 > 104.208.223.97.41874: Flags [.], ack 51, win 502, length 0
03:44:01.805029 IP 10.10.3.11.53 > 104.208.223.97.41874: Flags [P.], seq 1:877, ack 51, win 502, length 876 54701*- 1/8/8 TXT "v=DKIM1; h=sha256; k=rsa; s=email; " "p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwNWmypz1wHj9ctQtXDRdP5d7g8oUe6k0rGQ+ytNWSwelDqKVZYjYTpAJMTOv8fjW9EAuv0RMbnvht0Shsas0Hx2VFxA/UKg3FiJHn7STkzP7gEOUDg3BB6VmegE0AJlvEDF6IOxr/lqF59s3XmgABv8OykTkDb7hAPXf995wmda4slKlntKz/o+chaJsT7WEQk2HjDy9UVPvys" "yMvJfG6Fj7YdxhibgZcfcyomGA2FlNvpWVF4r/2FnBZT9VCYMMNKwYJd294rlwZIBiz1MYigJ3sqMEqUxp/ZTWXK8PidY/KrybkieEkB2pcK863kwniKpl5Nsh85weH1JiaU1rSwIDAQAB" (874)
03:44:01.827599 IP 3.228.170.24.37482 > 10.10.3.11.53: 5466% [1au] A? d.ns.domainmail.org. (48)
03:44:01.827838 IP 10.10.3.11.53 > 3.228.170.24.37482: 5466*- 2/9/13 A 107.191.108.110, RRSIG (1137)
03:44:01.863034 IP 104.208.223.97.41874 > 10.10.3.11.53: Flags [.], ack 877, win 2049, length 0