I appreciate you for sharing your concern with us, @mikeotaylor

I'll make sure you can send an acknowledgement or receipt to your client when their invoice has been paid. 

I recommend logging out and logging back in to your QuickBooks Self-Employed (QBSE) account. This refreshes the system and for the updates to take effect. 

If this is not the case, I suggest accessing your account via a private or incognito window. This way, we can check if this is a browser caching issue. 

Too much data from your browser causes issues that affect the view and performance of your account. Using a private window helps us verify the issue as this doesn't save any cache data. 

To open a private window, please refer to these keyboard shortcuts: 

• Ctrl + Shift + N (Google Chrome browser)
• Ctrl + Shift + P (Mozilla Firefox & Microsoft Edge browsers)
• Command + Shift + N (Safari browser)

If you’re able to view and send an acknowledgement, I’d recommend clearing your regular browser's cache to refresh the system. If the issue remains, I suggest using other supported browsers. This way, we can check if this is a browser-specific matter.

Once everything is in place, you'll want to check out this article that can aid you in organising your transactions: Categorise transactions in QuickBooks Self-Employed.

I'll be around to back you up if you need more assistance managing your invoices or your QBSE account. Keep safe and have a jolly day ahead!