Does it think you are amending? Delete the amended return.
How to delete an Amended return in the Online version
https://ttlc.intuit.com/community/amending/help/how-do-i-cancel-or-undo-an-amended-return-in-turbota...
You should have clicked on Add A State to get back into your return. Then How to change from Mail to Efile
https://ttlc.intuit.com/community/e-file/help/how-do-i-change-from-mail-to-e-file-in-turbotax-online...
