Are you using Cloudflare in front of your site? If so, the IP you’re seeing is Cloudflare’s and not the bot’s IP. You’d need to log and check the headers that Cloudflare sends you, i.e. x-forwarded-for and cf-connecting-ip.
As to how one IP can originating from multiple locations: anycast.
As to how one IP can originating from multiple locations: anycast.