Welcome back, @BDLHOLDINGS.
QuickBooks Online was made around Google Chrome, so that's why we always recommend using Google Chrome as your go-to browser for the product.
If you're trying to fix the Print and Preview button on the Safari browser, then I suggest clearing your browsing data. Your browser can store data over some time that can cause glitches or error messages.
Here's how to clear your data file within the Safari browser:
It's that easy!
This link may come in handy about printing invoices.
I value you and the success of your business. Remember, I'm only a comment away if you need me. Enjoy the rest of your day!