"401k repayment not income if paid back by due date of your tax return. Is that correct?"

Yes, that's what I told you in your original topic, here:

https://proconnect.intuit.com/community/proseries-tax-discussions/discussion/loan-from-401k-paid-off...

No need to start it again.

"But under the Tax Cuts and Jobs Act, you don’t have to pay taxes or the penalty if you repay the loan by the due date of your tax return for the year when you leave your job (including extensions). For example, if you leave your job in 2019, you’d have until April 15, 2020, to repay the loan (or October 15, 2020, if you file an extension)."

Otherwise, the reason it would be reported as taxable income, is that you Took the money, but didn't repay it, so that is the same as Taxable distribution. It is "deemed" to be a distribution.