@defunct78 Adding more details to my post.
tcpdump on the inside shows the ServFail as stated. Enabling TLS causes these errors. Again, DNSSEC has always been disabled.
13:48:47.739211 IP (tos 0x0, ttl 64, id 57751, offset 0, flags [none], proto UDP (17), length 59, bad cksum 0 (->dab3)!)
192.168.X.254.53 > 192.168.X.24.63104: [bad udp cksum 0xbe9f -> 0xb98a!] 11684 ServFail q: AAAA? i.ebayimg.com. 0/0/0 (31)
and IPv6
13:32:22.688367 IP6 (hlim 64, next-header UDP (17) payload length: 41) XXX:XXX:XXX:30::1.53 > XXX:XXX:XXX:30:f470:14f5:f634:1308.55800: [udp sum ok] 5238 ServFail q: AAAA? ssl.gstatic.com. 0/0/0 (33)
I am not seeing errors on the WAN side, though that data is encrypted so it is a bit harder to see the content. I have tried Quad9 and Cloudflare both. Also disabled IPv6 on the client side just to isolate the issue, none of these seemed to have changed the behavior.