[Samba] Suddenly can't delete reverse DNS records via DNS Mgmt MMC?

[Peter]

Hi! Looking for advice, I have a set of Samba DCs (4.15.13, using
dns-backend=BIND9_DLZ, stuck on this version until the next distro version
is approved for use). These servers have been in production for about 6
years now without any issues. However, starting yesterday, I noticed that I
am no longer able to delete reverse DNS records using the Windows 11 24H2
DNS Management MMC console. I can still delete (and create) forward
records.

When I try to delete a record, I get this message: *"The record cannot be
deleted. The local security authority database contains an internal
inconsistency"*. I get the same error on both DCs.

The only recent changes I can think of prior to this issue were: 1) distro
vendor upgraded glibc, 2) bind9 on the DC with the FSMO roles needed a new
rndc.key (I don't remember the exact message, but most 'sudo rndc' commands
resulted in an error stating there was some sort of cipher mismatch, and
setting up a new rndc key resolved the issue).

Any suggestions?

Thanks,

Peter