The connection shows as “aborted” for me, so it’s likely some issue with the certificate. I’d suggest loosening up a few things and then test one after another. Since the connection is being aborted quickly, I’m guessing it’s going to be more related to the key pinning you’re doing or some other basic-level issue.
Recently I was having my site not loading in Firefox (but I didn’t try anything else), so I recreated my private CA from scratch. Then I realized the problem was with nginx conflicting parameters related to elliptic curves and session resumption.
Whenever your nginx-powered site doesn’t load without a single browser error, inspect TLS configuration first, don’t mess with certificates, unless you want to waste your time.