[Samba] samba_dlz b9_format: unhandled record type 0

[Ing. Claudio Nicora]

Dual Samba 4.7.6 AD DC on Ubuntu 18.04 Servers + Windows 2008R2 DC.

Looking at Samba logs I've noticed a lot of these lines on first DC:
---
Jul 31 11:08:25 srvaddc named[32168]: samba_dlz b9_format: unhandled record type 0
Jul 31 11:08:25 srvaddc named[32168]: message repeated 92 times: [ samba_dlz b9_format: unhandled record type 0]
...
Jul 31 11:19:12 srvaddc named[32168]: samba_dlz b9_format: unhandled record type 0
Jul 31 11:19:12 srvaddc named[32168]: message repeated 100 times: [ samba_dlz b9_format: unhandled record type 0]
---

Thanks to rsyslog compacting identical and repeated log lines by default on Ubuntu (the "repeated x times" part), this issue didn't leap out immediately.
I'm actually a bit worried since it repeats each 10/15 minutes with about 100 (compacted) lines each, so I'm investigating on it but... no results.

The only relevant result I've found is this message from L.P.H. van Belle in 2014:
https://lists.samba.org/archive/samba/2014-January/178027.html

@Louis: did you fix the issue on your side?
@all: what shall I do?

Cheers
Claudio