I have a domain registered with Cloudflare. The second level domain points to a site hosted at Firebase. It works fine.
A subdomain points at my home NAS via an A record. The load time when I go through The A record at Cloudflare is terrible. When I go to the same nas through a DDNS provider (noip.com) it is really fast. So I’m assuming that I need to change some settings on Cloudflare?
In fact, some elements don’t seem to load at all going through Cloudflare.
Both the second level domain and the subdomain are proxied 
.
I have a certificate installed on the NAS for the DDNS provider. The subdomain on Cloudflare has a valid cert.