Hi Basara and sorry for the delayed reply...
When I resize the window to observe how the store responses to the various screen sizes... when I reach the size of a mobile, instead of the fallback banner to kick in (as it happens in your demo), it just does not happen...
No fallback banner appears and that part appears to be messed-up somehow... although I also did follow the instructions of the documentation...
On top of that, it shows as a 6th main banner...