DNS name on IPaddress created by netbox script

[DC-Rasmus-Elmholt]

I have a strange issue when I create an IP address in netbox and add a DNS name and tag to it. I am sure there is a good explanation but I have not found it yet.

I create a device and two sub-interfaces and add IP addresses to those interfaces with the following code:

device_name = "test-device"
address_prefix = "10.0.0."

device = Device(
    device_type=data["device_model"],
    name=device_name,
    site=data["site"],
    status=DeviceStatusChoices.STATUS_ACTIVE,
    role=role,
)

device.save()

lan_interface = (
    Interface.objects.filter(name="GE2", device=device).first()
)
for number in [3,5]:
    lan_vl_interface = Interface(
        name=f"GE2.{number}",
        type="virtual",
        parent=lan_interface,
        device=device
    )
    lan_vl_interface.save()
    self.log_success(
        f"Created interface: "
        f"{lan_vl_interface.name}"
    )

    #
    # Interface IP
    #
    address = f"{address_prefix}{(number+13)*4+1}/29"
    ipaddr = IPAddress(
    address=address,
    vrf=data["site_vrf"],
    assigned_object=lan_vl_interface
    )
    ipaddr.full_clean()
    ipaddr.save()

try:
    ipaddr.dns_name = f"ge2-{number}.{device_name}.domain.com"
    ipaddr.tags.add("DNS")
    ipaddr.save()
except Exception:
    pass

It creates the device, add the two sub-interfaces and IP addresses and adds the DNS name and Tag in one change, but for some reason it deletes the dns_name afterwards.

This is the first change in the Request ID:

Within the same Request ID it removes the DNS name:

I cannot figure out why it within the 3 same lines of code sets the DNS name, adds the Tag and saves, but somehow it is 2 changes, and one of them removes the DNS name again.