Servers in question are 2012. After reboot or DHCP service reset DNS records are created for exactly 59 minutes and 30 seconds. After that all updates fail with the following prompt in the DEHCP log. If I restart the DHCP service DNS registration works again for 59 minutes.
31,04/08/21,16:13:09,DNS Update Failed,<IP Address Redacted>,<Host Name redacted>,,,0,6,,,,,,,,,2
There are two dhcp servers in a fail over cluster...lets call them dhcp1 and dhcp2.
On the DNS tab for the scopes Always dynamically update DNS records is set.
Name protection is NOT enabled.
The DHCP servers ARE members of the DNSUpdateProxy security group.