So prior to coming to Enhance I was using ServerPilot.io for hosting a small handful of sites. Doesn't really support letting customers login, uses nginx. But it automatically supports Cloudflare Proxy, so the logs are showing the actual customer IP addresses.
I moved several ConcreteCMS sites to Enhance and started fighting with getting logged out all the time of Concrete. What I found was that Enhance isn't detecting the original visitor IP, it's pulling Cloudflare's proxy IP, which is always changing. I have fixed this for now in Concrete by turning off session invalidation on IP change.
But Enhance should auto detect these forwarded proxy headers, or have the UI give us the option to enable that. I realize some folks may use other proxy services, which would also be in the same boat.
Currently using Apache in Enhance.
Just to make sure I wasn't crazy, I did go peek at the webserver logs in Enhance to confirm.