Hi there, a-frontlineps and @Ken62.
Some users have reported that they're unable to email invoices. We’ve identified the source of the issue and are working to fix it.
Alternatively, you can download the invoices as a PDF and attach them to an email outside of QuickBooks Online (QBO). You can visit this page to learn more about the progress of the investigation: https://status.quickbooks.intuit.com/.
I appreciate your patience while we're working on this. Don't hesitate to visit the Community again if you have other QuickBooks concerns or questions. I'll get back to lend a helping hand.