Disconcerting when something does not work as expected. Worth a .

Suggest waiting a bit on doing a clean install of Win 10, but doing so will increase stability and response times. Problem with an upgrade is that, if something does not work as it should on the original os system, there is a chance it can get carried over to the new upgraded os.

Some are already reporting a bit slower boot times after upgrading. Clean install will fix that issue.
https://forum.avast.com/index.php?topic=156141.msg1238602#msg1238602