Hi. After updating on the 22nd of January to WHMCS 7.7, we started experiencing a really weird issue. A couple of clients only paid for small part of their total due, but the amount paid was matching other client's unpaid invoices. After investigating we found out that a bunch of our clients'  subscriptions suddenly started paying for the wrong invoices in WHMCS. According to my research, this started happening when the cron job ran after upgrading. We've had to cancel all PayPal