Attempted to file 2020 1040-X but was rejected by the IRS. IRS Error Detail says the 1040-X was rejected because the "Amended Return" checkbox is not not checked. Therefore, a duplicate TIN was detected as the original return has been previously e-filed. 

However, the Federal Information Worksheet, Part VII, shows that both of the checkboxes under the Federal Amended Returns: 1. File federal amended return electronically and 2. Original return was successfully e-filed are both checked.

Is there another box to check. The file return electronically checkbox in Part IV is checked.

There is no 2020 checkbox shown at the top of the printed Form 1040-X.

Has Intuit not updated their forms?

Is it too early to file a 2020 1040-X, maybe?

Has anyone had this issue?

Thanks,

James