Force Edge to do not redirect HTTP → HTTPS

A quick note on all steps needed for making sure that Edge won’t do any HTTP to HTTPS redirect:

1. Set Automatic HTTPS (edge://flags/#edge-automatic-https) to Disabled.
2. Disable HTTP Strict Transport Security (source):
   • Go to Net Internals → Domain Security Policy (edge://net-internals/#hsts).
   • Enter domain name into Domain field in Delete domain security policies and hit Enter (source).
   • Enter domain name into Domain field in Query HSTS/PKP domain and hit Enter to validate (source).
3. Press Ctrl+Shift+Del, and delete all cache and browsing history (source).
4. Add your domain in Insecure content (edge://settings/content/insecureContent) → Allow list (source).
5. Restart Microsoft Edge.

If after above your domain or page is still being redirected to https:// after you specifically type http:// in your URL then there’s 99% chance that the redirect is server-side and there is nothing more that you can do prevent it on the client side. Sorry!