Microsoft Edge’s update server is suffering a worldwide outage preventing users from updating to version 90 of the web browser. Users have been unable to autoupdate the browser and are instead greeted with the 0x800421F7 error. Microsoft is aware of the issue and stated that they are working on the problem. Some users have been able to get it to work by trying to perform the update a few times. The servers are now back up and running you can now update Microsoft Edge again.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-edges-update-server-is-down-shows-error-code-7/