Hello,
it appears that the UE Documentation search no longer works. When searching for example for Lightmass in the top right search box, it brings me to the results page, which shows Lightmass link as the first one: https://docs.unrealengine.com/en-US/BuildingWorlds/LightingAndShadows/Lightmass/Basics/index.html
But when I click it, it brings be back to the documentation home page. It’s not very surprising, since the search uses Bing, one of the worst search engines, but still I think this should be fixed 
As a bonus bug, the Theme switcher between bright and dark at the bottom left doesn’t seem to be working anymore either.