Hi @ben74
Glad to know your issue has been resolved.
You can have free SSL from LetsEncrypt which works across all browser. Following command will help you to do that:
ee site update example.com --le
With above command EE would create an SSL certificate and move your site to HTTP/2 .
As your current query has been answered, I am closing this topic. Feel free to create a new topic if you any other questions.
Thanks