Invoice has been emailed but is not showing as being sent?

Thank you for taking the time to post here in the Community, @botanicum-live-c. I'll be happy to help you.

With regards to your concern, it is possible that there's a delay with sent status of your emailed invoice. That is caused by cookies and caches. For now, we can try to perform some basic browser troubleshooting that will help your browser work better and faster.

You can follow the process below:
 

1. Restart your browser.
2. Log in to your account and try connecting to the Amazon transactions feed in an incognito or private browser. You can use these keyboard shortcuts to launch a new private window:
   
   Google Chrome: press Ctrl + Shift + N 
   Mozilla Firefox: press Ctrl + Shift + P
   Safari: press Command + Shift + N
    
3. If it works, go back to your regular browser and clear your browser's cache then check again if you can see the sent messages.
    

If the issue persist, I'd like to know if you get an error message? If so, It'll be great if you can provide us some screenshot. This way, I can provide you with a resolution that fits your situation. Any additional information will be highly appreciated.

Furthermore, you may want to customise the appearance of the sales forms that you send to your customer. Learn from this article for your guide: Customise Invoices, Quotes, and Sales Receipts In QuickBooks Online.

Feel free to post a reply if you have clarification or additional information with your sent invoices. I'll be glad to assist you. Have a good one!