When receiving money for invoice, the amount is auto-entered as a negative therefore doubling the amount the customer owes instead of leaving a zero balance.
It will give more clarity if you could upload screenshot of your invoice.
Here it is.
While applying payment was the unit price entered manually? I am sure it is a manual error when entering the value. Try deleting and applying the payment again.
@sparky is right.
Manager creates a negative amount when creates the receipt, i.e. puts -77.00 instead 77.00.
If you remove the minus sign, it’s all good.
the latest update seems to have this bug.
I tried to reproduce it. When we receive money from the cash accounts and select the invoice, the value does not auto-populate. But when receive money for an invoice from the sales invoice module, the unit price is automatically populated with a negative value.
Sorry about this. Fixed in the latest version (17.6.3)