Who do your IP loggers log Cloudflare IP's instead of the real IP from the user?

Depending on where you have posted your link, most services make proxy requests to get meta data from the link you have posted. Let's take Discord for example. Discord uses proxy to get and build embeds to show what kind of website you might visit. If you for example post the link from the IP logger you might see some IP addresses in your logs, you are not looking for. Those are proxies used by the platforms you have posted the link. You only start to see the IP address from a client once they have clicked on the link, that's how IP loggers work.