The view you're seeing may have been filtered. Let's check if this is the case. Here's how:
Navigate the Sales tab and select All Sales.
Click on the Filter drop-down arrow.
Make sure to select All transactions in the Type drop-down and All customers in the Customer drop-down.
Hit on Apply.
Doing these steps, you'll have the lists of all customers as well as the type of transactions.
If you're still getting the same results, let's determine if this has something to do with your browser's cache. Open your account using a private browser to check if you have your customer lists. If you do, I'd recommend clearing your browser's cache. It eliminates excessive files on your browser. As an alternative, you can also use other supported browsers.