I read the same thing on the IRS website. I don't believe return data goes directly from your Turbo Tax software to the IRS. Instead, it goes to Intuit servers first, and then they forward to the IRS. Apparently Intuit dropped that service in October 2020. Pretty frustrating! What good is having e-file available if your software provider drops that service?
P.S. Don't expect for your amended return to get processed any time soon after mailing it. I mailed three 2019 amended returns in late July last year and none have been processed yet.
