Dunning Interest Column on appears on Customer Receivables Ageing

In 8.8 Customer has a column appearing on Customer receivable report titled 'Interest' only thing is the column shows no interest whatsoever and is blank known reasons for this as I have tried to replicate but can't even get the Dunning interest to appear no my demo system so I can see the result on customer data but can't replicate as can't even get column to appear.