Why does the Retry get stock button appear

Why does the "Retry get stock" button appear

Amazon has recently made changes to how it displays the offers listing page which will cause the stock checker to sometimes display the seller name but no stock quantity. 

When AZInsight finishes scanning and detects that is unable to get stock quantity for some sellers, it will display a Retry get stock button. Click this button and AZInsight will retry to get the stock for the sellers that are on the Stock Checker Table but show no stock quantity for.