Dynamic DNS PTR records are not being created


I have a a UCS server acting as a the primary DNS and DHCP server. I have 4 different reverse lookup zone subnets. When I log a Windows machine onto the domain and the DHCP server issues an IP, it correctly updates the DNS Forward lookup zone but does not add a record in the Reverse lookup zone.

the syslog shows the update on the AAAA and A records but has no log of attempting to update the PTR record.

Any ideas on why this is happening or how I can investigate this further?