One thing to be aware of is, if you’re using a CDN (or at least with cloudflare) it’s possible that their edge server IPs are seen by your discourse install… vs the visitor’s IP.
So if you perform a “ban user and IP address” you can run into issues as you have effectively banned that edge server from your discourse install, along with any users that happen to be routed to it.
That said, I believe there is a way to fix this, but I can’t recall the process.
But nonetheless, something to look out for if you or your users report that they are being blocked from your site.