Problem
You are trying to clear out credit for a customer. You created an adjustment invoice for the invoice, added a task with an amount equal to the credit, and went back to the original invoice to collect and apply payments. However, you do not see the credit to apply.
Solution
Unapply the payment so that the full amount goes to the customer's available credits since the payment is already exported and cannot be edited.
On the original invoice, select Collect and apply payment and choose the credit. Apply only a partial amount.
On the adjustment invoice, add a task for the remaining amount. Adjust the pricing as needed to account for taxes.
Navigate back to the original invoice and select Collect and apply payment.
Apply the remaining credit to the adjustment invoice.
Note: If a customer makes a payment that should have created a credit for them, check if the payment was fully applied or not.