AR Cash Receipts - Sage Premier 2017 Ver 5.40.2.0

A very odd error that I believe is a bug - the customer received payment towards an invoice several months prior and properly shows a zero balance for that invoice. Now a new payment is received from that customer. If you look at Customer Inquiry, everything looks correct. But when selecting invoices to pay in the Cash Receipts Entry program, the payment amount previous received, often several months ago, is showing in the list as an outstanding credit balance. For example, invoice 12345 for $1,000 was paid in full in Sept. 2017. Now a new AR cash receipt is being posted. When the list of outstanding invoices screen opens, invoice 12345 shows an Inv Amount of $.00 but an Inv Balance of ($1,000.00). After some checking, it appears the problem occurs in the AR_CashReceiptsHistory table. I'm just wondering if anyone else has encountered this problem and if they have a solution.