You printed and mailed an amended tax return in February of 2019 for the 2018 tax return? Or are you referring to the original 2018 tax return you filed in February?
Did you print and mail an amended return in April? Or did you just change the original tax return that was filed and expected to see the changed return e-filed? It could not have been e-filed if you already e-filed another return the tax return was accepted by the IRS.
Did you follow the procedure in the following TurboTax support FAQ for amending a 2018 tax return using the online editions - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-turbotax-online-return/01/27577
Federal amended tax returns, Form 1040X, can Never be e-filed, they must be printed, signed, dated and mailed by you to the IRS.
When you sign onto your online account and land on the Tax Home web page, scroll down and click on Add a state.
This will take you back to the 2018 online tax return.
Click on Tax Tools on the left side of the online program screen. Then click on Print Center. Then click on Print, save or preview this year's return. Choose the option Include government and TurboTax worksheets
