Good news! An update currently planned for April 12th, 2019 will resolve the issue of a looping interview preventing e-file. You may still see a warning of excess contribution, but e-file will be available.
You can check out this TurboTax FAQ for the latest info: Excess 401(k) Contribution Preventing E-filing.
[Edited 4/10/19 | 1:36PM EST]
