I’ve touched on this before but it was never resolved. The “purchase invoice total” on the dashboard takes you to your current list of unpaid invoices but if you have credit notes applied to an account it ignores those and does not show you the actual balance you owe (which is what it says on the screen that you gets you to the page in the first place).
There is also no sign that there is even a credit note on the account that you need to manually take into account. So “Total You Owe” is incorrect, it is “Total Of Invoices Excluding Credits That Might Be Hidden”. The only way to get to find out about the credit notes is to click all totals on the screen and see of any of them change, and then manually total up the balances (ignoring the total from selecting the check boxes).
This screen should really show what you actually owe. Either it needs columns adding for the total balance of the invoice as well as the invoice total or you should include the credit notes (as per the suppliers invoice screen).