EDIT: Thanks I'll look into the nginx redirect part, and see if I can find a way to disable HSTS as well due to the below issue I had just posted. Unless someone knows a quick way to disable HSTS?
Another, separate issue - I use my www.mydomain.com as kind of a shortcut page to other services, e.g. a shortcut on there links to my UniFi setup, which runs HTTPS on a different port than 443, and obviously doesn't use the same certificate. When I try to browse to that site I get
Because this site uses HTTP Strict Transport Security, you can’t continue to this site at this time.
That's in IE, and in Chrome it shows
You cannot visit mydomain.com right now because the website uses HSTS.