An amended federal tax return,Form 1040X, can only be printed and mailed by you to the IRS, it can never be e-filed.
Only your original tax return can be e-filed. The TurboTax indication that the e-filed return has been accepted is only for the original tax return -
https://turbotax.intuit.com/tax-tools/efile-status-lookup/The IRS website for status of tax refunds is only for original tax returns filed, not amended returns -
https://www.irs.gov/refunds