I appreciate you for sharing the details of your concern, @Johnnyj. 

Let me provide some details about this invoice delivery issue. I'll also share some alternative steps as a workaround to ensure you can accomplish your goal.

The issue of invoices not being sent or having a delivery issue is tagged as an ongoing problem. Our Engineering Team is aware of the matter, and they're looking into it and are working to implement a solution that will resolve this issue. Please know that this is a high priority for us and it will continue to be so until it's fully resolved.

In the meantime, you can use one of the following workarounds to send your invoices:

• You can save your invoice as a PDF and send it via email through your business or other email address.
• You can send your customer a link to their invoice through SMS or messenger service. Simply click on “save and share link”, then select “copy link” and paste it into your SMS or messenger service.
• If you have a Gmail or G-suite email account, you can use the send with Gmail feature to send invoices from your own address.
• You can save your invoice as a PDF, print it, and send it to your customer via mail.

Then, I suggest contacting our Technical Support Team if you haven't reached them yet. This is to ensure they can add you to our notification list. This will help our engineers determine the number of affected users. You'll also receive an update via email once this has been resolved.

You'll also want to personalize the appearance by adding specific info to your sales forms in QBO. Check out this article for more information: Customize invoices, estimates, and sales receipts in QuickBooks Online.

Please let me know if the workarounds I've provided work for you. I'm here whenever you need help with managing your invoices in QuickBooks. Take care!