"Treat risky downloads over insecure connections as active mixed content" break Extension Store

If "Treat risky downloads over insecure connections as active mixed content" aka "edge://flags/#treat-unsafe-downloads-as-active-content  in edge://flags/  is enabled, no extension's from new https://microsoftedge.microsoft.com/ can be installed.

After clicking on download, a popup with "Download canceled" appears and that's it.

Are the extension's provided over HTTP or why did this flag break downloads from Store?