round-robin bug in 9.12.1-P2 for rDNS?

[Mark Boolootian]

Hi folks,

I have a funny issue that looks buggish
to me.  I have an RRSET with two
A records that our auth DNS servers happily
round-robin, which can be observed with

dig unix.lt.ucsc.edu @adns1.ucsc.edu

However, our recursive DNS servers, with
the same rrset-order config will not round-robin
these records.

BUT, if I add a third A record, the rDNS servers
then round-robin.

I can punch in some config elements here if
it is useful, but this smells like a bug, and
maybe I should be reporting on gitlab.

Thoughts?

mark