False positives with CloudFlare

I just noticed that at least one of our users was flagged as a false positive. It appears her recorded IP was shared by several users within a short timeframe, and it also appears the IP is coming from CloudFlare. Just one hour before this user tried to create an account, the same profile (IP + browser type—chrome on android) was flagged for vulnerability probing. I just found the WP Cerber article (https://wpcerber.com/cloudflare-and-wordpress-cerber/) describing how we should set "I am behind a reverse proxy" to true in the settings, and I have done so. Will this take care of this issue? Should I also turn on the wp-cerber cloudflare add-on (https://wpcerber.com/cloudflare-add-on-wp-cerber/)? There are warnings about installing the add-on, and I don't want to do anything that will adversely affect more users...