F12 tools fails to report HTTPS compromise

Thanks for the feedback and please accept our apologies for the delay in responding to you on this item.

At this time I do not see any errors in the console, though I do see the fonts you are referring to being loaded in the network tab.  We are wondering if there is some kind of difference in our environments that is responsible for this.  Or possibly something in the page has changed that fixed this.

All the best,
The MS Edge Team

Clear your cache entirely. HSTS has recently been enabled for www.microsoft.com so if you do not clear your cache you likely have HSTS cached which translates the requests from HTTP to HTTPS mitigating the compromise. On a system running RS1 14393.5 and a completely cleared cache, Edge will fetch from the following when accessing this page

https://developer.microsoft.com/en-us/
https://developer.microsoft.com/en-us/devmsft.css
https://www.google-analytics.com/analytics.js
https://c.microsoft.com/ms.js
https://i.s-microsoft.com/fonts/segoe-ui/west-european/bold/latest.woff2
https://i.s-microsoft.com/fonts/segoe-ui/west-european/normal/latest.woff2
https://i.s-microsoft.com/fonts/segoe-ui/west-european/Semilight/latest.woff2
http://www.microsoft.com/fonts/segoe-ui/west-european/Semilight/latest.woff2
http://www.microsoft.com/fonts/segoe-ui/west-european/bold/latest.woff2
http://www.microsoft.com/fonts/segoe-ui/west-european/normal/latest.woff2

The F12 console reports a compromise for the last request only. The first two HTTP font requests are not reported.