IPs addresses in my network not showing up in Pihole

Hi,

I am using Pihole docker as a dhcp and add blocker. I have the IP range of 192.168.10.3-192.168.10.251 available for DHCP leases.

Now, I have a device with IP 192.168.10.253 in my network. It seems to be an apple device, since this device is trying to talk to an apple IP address which is blocked by my firewall.
I also have some other IPs from within the IP range which a re not showing up in the currently active DHCP leases page on pihole. Who can that be?

I do not have any device with fixed IP settings on the client side. I set static DHCP leases on pihole.

If you run below one, the fifth column will show MAC addresses associated with corresponding IP's:

ip neighbour

You can lookup MAC addresses on below sites to figure out vendor/brand names:

Do mind though that some devices apply MAC address anonymization (some Apple products do).