Can anyone tell me why, when I send an invoice with all the information, eg time & hourly rate, why don't they receive the information at the other end?

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: 

1. Click the (?) Help icon and choose the Talk to a human option (then type it again when prompted).
2. When asked by the bot, type "Invoice", then select I still need a human.
3. Proceed with Contact us.
4. Click Let’s talk then choose either Get a call or Start messaging. 

For the old "Help" menu:

1. Click the Help icon and select the Contact Us button.
2. Type "Invoice" in the What can we help you with box.
3. Proceed with the Let's talk button.
4. Select either Start messaging or Get a call button.

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!