Windows updates released this month are causing some GOV.UK sites to become unreachable due to the GOV.UK TLD being added to Microsoft’s HSTS preload list. This causes Microsoft Edge and Internet Explorer to only connect via HTTPS, which some of GOV.UK the sites do not support, and thus making them unreachable. […]

from https://www.bleepingcomputer.com/news/microsoft/some-govuk-sites-unreachable-due-to-hsts-changes-in-windows-updates/