my network is looking for ipv6.broadband.voyager.nz but it doesn't exist

tcpdump

Time    Source    Destination    Protocol    Info
19:55:28.082454565    kali.1server.nz    ff02::1:ff22:a381    ICMPv6    Neighbor Solicitation for 2406:1e00:b910:fc00::22:a381 from f0:92:1c:f4:7a:a0

wireshark

Time    Source    Destination    Protocol    Info
19:55:26.137164258    kali.1server.nz    ipv6.broadband.voyager.nz    TCP    47739 → 80 [ACK] Seq=1 Ack=1 Win=1024 Len=0

kernal logs full of this

2026-03-15T19:56:42.664783+13:00 kali kernel: neighbour: ndisc_cache: neighbor table overflow!

i have /56 & /64 allocations

what other info is needed please?

cheers

edit:

nothing in the openwrt router logs about ipv6.broadband.voyager.nz