I think the 4x4 and 8x8 are measured from flat side to flat side.
I'm not at work right now so I can't measure if your larger measurements are from sharp edge to sharp edge but I think our 21-984-015 and 21-998-015 are the same beads that you bought elsewhere...
However, we are out of stock. We have 2 huge shipments of hematite coming ocean freight so it will be some weeks before most of our new stock arrives. A smaller amount of a few items is coming by air. The Temporarily Unavailable note suggests they are not in the air shipment and maybe not being made currently by our Taiwan manufacturer.
Give us a call after 10 am Pacific time, ask for me personally and maybe I can suggest an alternative source.