I encountered this same problem with my PA state form. This is a flaw in the program that you have to override by first clicking on the Forms icon in the upper left corner of Turbo Tax in order to display the Federal and state tax folders. Then click on the > Pennsylvania Forms to expand the folder.
Scroll down to the Tax Pymt Wks form and click on it. In my case, Line 15 was auto-filled with the date 04/15/2020, which was a date that had already had passed. Under the Edit pull-down menu of Turbotax, click on Override, which will allow you to change this date. Click and drag across the incorrect date to highlight it and re-type the present or future date when you will file the return. Hope this helps you.
