It does make this blanket statement at least somewhat incorrect:
"Support is limited to the country you purchased the device in"
But it certainly doesn't invalidate your poor experience, which sounds very frustrating.
That said, your video looks familiar. Does it go away if you disconnect and reconnect the keyboard? Every once and a while I have to do that.
I'm glad you had a good experience, but this does not make my poor experience or what Microsoft UK has repeatedly told me 'incorrect'.
My case number is 1378118289.