When I need SSL certificates on my website, I purchase certificates from GoGetSSL.com. Most of my SSL certificates are Sectigo Positive SSL, previously called Comodo. It is a very good deal. $7.90 for two years. Back to my topic today, I like to use ECC SSL instead of RSA SSL.
I have a site with https only. And at the same time I am using AWS CloudFront as CDN. One issue I met is 502 Bad Gateway error. After the Googleing and research, I found the reason of it. The real reason is AWS Cloudfront just support certain Encryption method.