This isn't the impression we want you to experience, @SimplyDan. I'm here to assist you with your concern in QuickBooks.

There aren't any changes in the system about emailing invoices with PDF attachments. However, there's an on-going issue about this, and our engineers are looking into this now to determine why attachments are not being sent with the emails.

I recommend contacting our Support Team and provide this investigation number INV-51962 so they can add your company details to the list of affected users. By doing this, we will be able to send you an email notification once an update is available.

Here's how you can reach us:

1. Click the Help icon in the upper right of the screen.
2. Select Contact US on the pop-up. 
3. Enter what you're needing assistance with in the What can we help with? field and choose Let's talk. 
4. Click Get a callback.
5. Enter your contact information.
6. Select Call me.​

Though, we don't have a specific estimated time frame on when this will completely be fixed. In the meantime, we can follow the workaround shared by our engineers to manually download the invoice payment receipt in QBO and send it to the client outside QuickBooks. 

Also, let's make sure to turn on the PDF Attached feature, just follow the steps shared by SarahannC on how to turn it on.

For more details about the different file types that you can attach to any transactions in QBO, please see this link: 

• What transactions can keep attachments?
• Email and customize sales form
• Fix errors when trying to send an invoice or estimate to your customers.

Thanks for your understanding and patience as we are doing our best to get this fixed. For any other concerns about QuickBooks, let me know by posting a comment below. I'm here to help. Take good care!