I understand the importance of working with templates we're comfortable with, @BRIANE1. 

Let me provide some additional insights on this matter. The reason why you're experiencing this is due to the new experience. QuickBooks Online has just transitioned to the new invoice layout. Thus, when we import invoices through CSV, QBO then sets the modern template as the default template. 

If you can switch to the old invoice experience, we use that as a workaround to manually add the invoices. 

We recognize how hard it is to transition to what we're used to, @BRIANE1. We value your understanding of these new changes. 

Moreover, I'll add this article about how to personalize and add specific info to your sales forms: Customize invoices, estimates, and sales receipts in QuickBooks Online. 

For further concerns about managing your invoices in QBO, please don't hesitate to comment below. Keep safe always.