BOM in Drawing - How to Refresh

Why don't the BOMs always update in drawings?  Sometimes I have to re-insert into the drawing to get it to update.  I tried rebuilding, saving, closing/reopening, checking assembly to ensure it's not marked to exclude, I also use top level only for BOM properties in both cases....This is a recurring issue I run into.  Anyone else experience this?

Oh and I checked the configuration.