DNS issue with openwrt.pool.ntp.org and AAAA queries

Invalid negative responses are returned to AAAA queries for the servers in this zone. The SOA record is for the parent zone not the delegated zone. With QNAME minimisation (RFC 7186) this is showing up in recursive server logs and is causing SERVFAIL to be returned to clients.

followed up in Wrong negative answers for 0.openwrt.pool.ntp.org AAAA (the duplicate posts was discourse being annoying)