Adding clients by ip but with hostname to client's list instead of using mac address

The issue I am facing:
Hi, I want to run two pi-holes on two different subnets. These subnets will be connected using a site2site VPN. This means, that we're goint over a gateway so identifying a client by it's mac-address isn't possible.

Unfortunally pihole adds clients by their mac-address by default instead of using the ip-address.
I understand it because ip addresses can change but in my case it results in:

So the pihole on site2 will only see the vpn-gateway's mac-adress, which doesn't match with this client. Rules behind the groups the client is assigned to will be not considered.
Of course I can add an IP-Adress of this client but manualy but I want to have the nice little hostname behind it (see screenshot) as the comment-field is used only for the interface name in my system.

Is there an option to add a client by ip-adress WITH hostname description behind when it's (at the moment) in the same network as pihole (so if pihole has the mac-address)?

Details about my system:

pihole  <---> site1 <---- VPN ----> site2 <---> pihole
          |                                 |
clients <-┘                                 └-> clients

What I have changed since installing Pi-hole:
Setting up ULA and custom conditional forwarding

Solved it: simply entering the ip address will add the hostname automatically. It worked fo whatever reason after clearing the cache in my browser.