I recently noticed that configuring that option works well if you create
the "Stock By" unit (for example 24-pack, 12-pack, box etc) first and later
add the retail unit (typically each or count). And that's ok for us in
most cases.
However, if you're trying to reconfigure an existing item that only had the
retail unit, when you try adding a Stock By unit and conversion formula,
the variation table is not mathematically correct. It just remains "messed
up" no matter what you do. The only thing that has worked for me is to
first reconfigure (rename) the existing unit from Retail By to Stock By and
add retail later.
