Xiaomi Smart Gateway V3 static IP

Hi!
I finally fixed all the BT temperature sensors via the Xiaomi Smart Gateway V3.
Everything works great. The problem is when we temporarily disconnect the power supply, then the Gateway obtains a new IP address.
HA can’t find more gateway. I must set manualy new ip address into integrations. I was on vacation now and didn’t notice for 6 days
How can I set a static address on a Xiaomi Smart Gateway V3?

regards Sved

See if you can add a static DHCP lease on your router.

How is this possible ? Router check mac address or how ?

Yes, the router is able to identify the client thanks to it’s MAC address.
How this is configured depends on your specific router. On Mikrotik routers, it is

/ip dhcp lease
print
# Find the correct dynamic lease. Let's say it's number 3.
make-static 3

The static DHCP lease then looks like this:

add address=192.168.1.111 comment=my_device mac-address=DE:AD:BE:EF:FE:ED server=LAN_DHCP

I will research in this direction. Thank you very much.
My wifi router is Ubiquiti UniFi…