DHCP Lease Time and Static Addresses

Hello! I’ve recently bought Mikrotik hAP ac2 and got such problem: I’m trying to setup remote Wake-on-lan for my home machine, I have a public static IP address and also I’ve set up port forwarding using NAT. But the trouble is that as I noticed it becomes impossible to forward port when the lease time of 10 minute ends after PC being shut down. In the DHCP list I’ve made the IP of that specific PC static (it is connected on ether2), also I’ve tried to make it static on ARP and also added it to the IP → Addresses list, but still no luck. I’m not that good at networking, so can someone advise pls on how to make the IP statically attached to that interface/MAC address? After end of DHCP lease Waking PC even on LAN becomes impossible