When I started using CloudFlare for DNS only, without any of their extras, they also did generate cert for my domain and it's impossible to disable this behavio

When I started using CloudFlare for DNS only, without any of their extras, they also did generate cert for my domain and it's impossible to disable this behavior through UI (requires contact with support). I did not expect that because I just wanted DNS, no traffic through them and I got a cert with my domain intermixed with some strangers.