Accounts receivable category arises when a bank transaction matches directly to an invoice, Driftingsky.

To begin, could you confirm if the transaction was directly matched to the invoice? If so, this could be one of the reasons why the invoice is categorized as (AR). 

In QBO, there is a customer workflow to follow where you create an invoice and then receive the payment to reduce the outstanding balance. You can also refer to this article for more information on properly recording invoice payments: Record invoice payments in QuickBooks Online. 

Let us know if you need more information about categorizing invoice payments in QBO. We're always here to help.