Reorder categories on home page

Just to save someone else some time. 

I got really stuck on how to do reorder categories on the home page (v3.0).

The intuitive option of dragging them in Ecard Management/Homepage Ecards wasn't working.  After lots of blind alleys, I (finally) thought of switching browser. Chrome wasn't working.  Tried on MS Edge and you can drag them into the order you want just fine.