I've just encountered this too. It's infuriating - how is TurboTax not held accountable for this? We're relying on their software and there's a clear error here that we're unlikely to pick up on when going through their system. What's the deal with the interest on the penalty, does anyone know? It seems unfair to be charged interest on a penalty for a 2017 return that I've only just found out about...
