Hi there,
Thanks for dropping by in the Community. I'd be happy to give you a hand with showing the QTY and Rate on your invoices.
First, I'd like to make sure your invoices are set up to show the two variables: QTY and Rate. To check this, click the Gear icon > Custom Form Styles > click Edit next to the invoice template you're using > navigate to the Content tab and make sure the Quantity and Rate tabs are checked. I'll attach a screenhsot below for reference:
Try this out and let me know how you make out. I'll be here in case you need futher assistance. Otherwise, enjoy the rest of your day! :)