@ahcproductions I was able to get one helpful link: 

https://quickbooks.intuit.com/learn-support/en-us/banking/nsf-check/00/619009

If you mainly receive epayments, ignore the articles about paper checks. Also, sometimes QBO flags an epayment NSF as a chargeback even though your customer/client is not disputing the invoice, so ignore the articles about chargebacks if theres no dispute. Third, if the initial epayment shows as posted in your bank stmt, you shouldn't delete the matched invoice. Create a new invoice to address the reversed payment and NSF, and match that invoice to the payment your client makes to correct the NSF issue.

Now I've got to board my flight!