Could you provide some details so we can look into this. Specifically what brows...

Could you provide some details so we can look into this. Specifically what browser and OS you are using, and any customizations you've made in your browser.

FWIW, the site is hosted on Cloudfront using an Amazon issued certificate. Here's some debug output I show using curl which shows successful negotiation:

  *   Trying 13.227.219.41...
  * TCP_NODELAY set
  * Connected to howhttps.works (13.227.219.41) port 443 (#0)
  * ALPN, offering h2
  * ALPN, offering http/1.1
  * successfully set certificate verify locations:
  *   CAfile: /etc/ssl/cert.pem
    CApath: none
  * TLSv1.2 (OUT), TLS handshake, Client hello (1):
  * TLSv1.2 (IN), TLS handshake, Server hello (2):
  * TLSv1.2 (IN), TLS handshake, Certificate (11):
  * TLSv1.2 (IN), TLS handshake, Server key exchange (12):
  * TLSv1.2 (IN), TLS handshake, Server finished (14):
  * TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
  * TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
  * TLSv1.2 (OUT), TLS handshake, Finished (20):
  * TLSv1.2 (IN), TLS change cipher, Change cipher spec (1):
  * TLSv1.2 (IN), TLS handshake, Finished (20):
  * SSL connection using TLSv1.2 / ECDHE-RSA-AES128-GCM-SHA256
  * ALPN, server accepted to use h2
  * Server certificate:
  *  subject: CN=howhttps.works
  *  start date: Feb 14 00:00:00 2020 GMT
  *  expire date: Mar 14 12:00:00 2021 GMT
  *  subjectAltName: host "howhttps.works" matched cert's "howhttps.works"
  *  issuer: C=US; O=Amazon; OU=Server CA 1B; CN=Amazon
  *  SSL certificate verify ok.