This is from Square/credit card data.  If you ring a sale and use a card that has been associated with a square account or another square vender the name and initial will show up and associate to the sale.  If you don't add the customer to the sale it will do this.  If you add the customer information to the sale then it will associate them together.  This can happen if they use multiple cards and you don't add the customer to the transaction.   This can also happen if you don't find the customer and create a new one.