Mac address/client already exist.

[gjkrisa]

I'm trying to route an ip Proxmox to my pi hole but it says the Mac adress or client identifier already exist.

I can't find it anywhere though if I do a search in dhcp leases by Mac it doesn't show anything. I can also put in any identifier name and still same issue.

now the odd thing is the ip for my device doesn't show up in dhcp leases but can talk to the internet.

if I had a duplicate Mac/ip wouldn't it still show somewhere?

what can I check to find this device if it not in dhcp leases?