Why does my IP keep changing when I play here.

I dont have a vpn but every week or so I get an email saying to authenticate but im playing from the same physical location. Im playing on a desktop.

xx.xxx.xx.xxx. Its the last 5 digits that change. the first 5 stay the same every time I authenticate.

That's on your end. Warmane CANNOT change your IP. Seems you're on a rolling IP, or non static IP. Fix that.