We have a problem with our auto-creation of the database. Whenever the domain is enabled in Cloudflare the auto-creation of the database will not work (can’t create database using cpanel uapi), but if the domain is paused database auto creation works just fine.
You are most likely trying to connect to a hostname which has been proxied. Either switch that record in Cloudflare’s DNS settings to or change the address in your application to go directly to your server.