I'm having the same issue! I was covered the entire year Jan-July with a marketplace plan that I have a 1095-A for and then Aug-Dec I was covered by my employer which I have a 1095-B form. TurboTax won't let me proceed without having the Aug-Dec boxes filled in with something.
I tried going around that by saying I was covered part of the year to see if it would give me the option to identify that I have both types of form and it doesn't.
