Interesting. I didn't know you could bypass the interview. Good to know for the future. I can't imagine why using forms vs the interview should make a difference though.
I suppose a possible difference between me and you is that you filed through Turbo Tax, and I filed through my accountant (I only use Turbo Tax for the what-if aspect). So as far as Turbo Tax knows, I haven't filed yet. But again, why would actually filing the return lock you out of a 2018 what-if? Must be something else.
Hope you get a response from Turbo Tax. If not, you might try creating a new topic specifically for your problem. They were very responsive when I first posted this topic.
Good luck
