Hummingbird not working on site (The performance scan didn't return any results)

Hi, we're getting this error when running the speed report: "The performance scan didn't return any results. This probably means you're on a local website (which we can't scan) or something went wrong trying to access WPMU DEV. Try again and if this error continues to appear please open a ticket with our support heroes"

It's happening both on staging & live environment.
We have enabled support access.

Please advise