Hey
After thorough review of UnrealEngine.com, I have verified that MMB opens the link you were hovering over originally. I also have verified that RMB by clicking on ‘open in a new tab’ also opens up the new link in a new tab. If you or anyone else happens to still be experiencing this issue, please let us know which browser you’re using, so we can forward this bug along to the proper department.
Thank you!