Customer Information screen displays transactions: Sales Order, Invoice and Payments, all in the same amount. Why are the Sales Orders treated as a transaction?

I'm here to help you get this sorted out, MikePeck.

Sales Order is a non posting Transaction. It's possible that it was filtered on ''All Transactions'' in your customer information screen.  You’ll just need to filter ''All Sales transactions'' to get the data you need.

To keep track of your sales and expenses, check out this article: Customize customer, job, and sales reports in QuickBooks Desktop. It provides different reports and how to customize or filter each of them to get the data that you need.

Feel free to open this guide to further assist you in managing your customer's transactions: Get started with customer transaction workflows in QuickBooks Desktop.

Please keep me posted on how things go after trying out the suggestions I've provided. I'm here to help you out again. Have a good day ahead!

@MikePeck  RE: Why are the Sales Orders treated as a transaction?

They are transactions. They're non-posting transactions, but there's still transactions.  

One of the primary uses of the list of transactions in the customer center is to locate and perhaps open/edit various types of transactions for a customer.

For the same reason, you'll also see Estimates and Invoices & Sales Receipts that are marked non-posting -> as a way to locate them in order to work with them.