Hi, @murkywaters-grea. I can share with you some workarounds to fix the issue you had with your customer's income.
Incorrect customer's income or balances happens when there are duplicate entries recorded. To isolate the issue, you can run the Transaction List by Customer report to see the transactions recorded under his or her name.
Here's how:
Click on Reports at the left pane, then open the Transaction List by Customer report.
Filter the dates, then review the transactions recorded.