Works fine for me as well.
Go to www.unrealengine and sign in, then click on the “Profile” tab. Make sure your GitHub user name is typed into the “GitHub Account Name” box, and it is case sensitive so make sure it is exactly the same, and then hit save.
After that you should be able to access the repo, entering your account into that field enters you into the “Epic Games” organization on GitHub. Hope that helps!