This week I moved my local development Sitecore 10 instance to a new laptop running Windows 11; all seemed well, except for XConnect, that mysteriously only worked without HTTPS. I would constantly get ERR_CONNECTION_RESET, with nothing being recorded in either XConnect, IIS or Events log:
All the while the TLS Certificate was reported invalid.
After extensive troubleshooting – covering pretty much every possible cause of XConnect misconfiguration – I tried almost by chance an option in the IIS Bindings menu that I did not notice in previous versions of Windows, “Disable TLS 1.3 over TCP”:
Apparently, Windows 11 adds support for TLS 1.3, and this prevents XConnect from working over HTTPS.
After consulting with the Sitecore Slack Community, I found at least one previous article on the subject, courtesy of Mr. Maarten Willebrands: https://www.maartenwillebrands.nl/2021/11/15/sitecore-running-sitecore-on-windows-11.