I have a server only have ipv6 address and add 2 AAAA record, one I used CF proxy another not. Now I can access my Nginx server without the proxy. If I use a proxy then get a 522 error code. When I use proxy my Nginx server can’t receive any requests, I checked the Nginx access log found no request. I think the key point is that the CF does not use the ipv6 server to proxy the client request, so the ipv6 client can access my server easily. I hope the CF team will handle this problem.
By the way, ipv6 is the future.