DDNS TTL value is does not meet 4702, Section 5
This was originally opened in trac:
But somehow did not get migrated.
Currently the value used as TTL in DNS RRs is TTL directly from the lease (valid lease lifetime). Per 4702/Section 5 it should be be:
RR TTL = ((lease TTL / 3) < 10 minutes) ? 10 minutes : (lease TTL / 3)