How to clear rDNS entries?

[Vexz]

I'm using AdGuard Home on my OPNsense and use Unbound for reverse DNS. It works fine so far but thanks to DHCP some devices get a new IP address sooner or later. The problem here is that AGH does not release old rDNS entries.

Example:
Let's say I have a device "Device1" which is configured to use DHCP and got the IP 10.0.0.20. AGH got it right and through rDNS saves that the IP 10.0.0.20 belongs to Device1. Now the lease expires and Device1 gets the IP 10.0.0.21. AGH makes a reverse DNS lookup and sees that Device1 now has the IP 10.0.0.21.
But now I have two entries for Device1:
• 10.0.0.20 → Device1 (deprecated but still there)
• 10.0.0.21 → Device1

Is there a way to clear the rDNS entries so AGH starts over to lookup up clients' IP addresses? Sooner or later this will just be a big mess with many devices changing IP addresses.