Why won't Turbo Tax let me file my state income as non-taxable even though I am active duty military and turbo tax tells me it is not taxable?

All of my W2 income is non-taxable for PA because I am active duty military. Turbo Tax even says this on the screen and has a box to change. However, it makes me uncheck this box and make it taxable under the review system. It will not let me file without fixing this unless I mail my returns which is ridiculous.