[Samba] Device ends up with multiple dns records and IP addresses

[Sebastian Arcus]

I have a server with:

Samba 4.9.4 in AD mode
Bind 9.14.2
ISC Dhcpd 4.4.1

Samba is configured to use Bind for the dns back-end, and dynamic dns 
updates from dhcpd->Samba->Bind are configured using the script at Samba.org

I have this strange situation where one of the printers has ended up 
with 11 records in the dns back-end:

# host SEC001599AB9439
SEC001599AB9439.ihs-uk.lan has address 192.168.51.184
SEC001599AB9439.ihs-uk.lan has address 192.168.51.176
SEC001599AB9439.ihs-uk.lan has address 192.168.51.179
SEC001599AB9439.ihs-uk.lan has address 192.168.51.144
SEC001599AB9439.ihs-uk.lan has address 192.168.51.241
SEC001599AB9439.ihs-uk.lan has address 192.168.51.229
SEC001599AB9439.ihs-uk.lan has address 192.168.51.231
SEC001599AB9439.ihs-uk.lan has address 192.168.51.172
SEC001599AB9439.ihs-uk.lan has address 192.168.51.177
SEC001599AB9439.ihs-uk.lan has address 192.168.51.235
SEC001599AB9439.ihs-uk.lan has address 192.168.51.182

In order to start troubleshooting, I can't get my head around which 
software is not working properly. Is it the job of dhcpd not to allow a 
same device to request a different IP, or is it the Samba script, or 
Samba, or Bind? Which one should normally prevent this from happening? 
Thank you much for any suggestions.