Good day, tsdimauro64.
I'm here to assist you with your invoices.
Let us check the invoice template to see if the fields, like the rate, are included. Go to the Gear icon and select Custom Form Styles. Please check the detailed steps here: Customise invoices, quotes, and sales receipts in QuickBooks Online.
Also, we need to make sure that we selected the right template before sending it. Open the invoice, click the Customise button and you'll see all saved invoice templates. Then, select the right one and resend it.
In addition, you'll want to send a copy to yourself first to make sure that everything's good. If you experience the same behavior, I suggest contacting our Customer Support to further check it.
The new "Help" menu interface:
For the old "Help" menu:
If everything's fine on your end, advise your client to update, repair, or re-install Adobe Reader/Acrobat.
Post again here if you need anything else. Wishing you all the best!