It’s possible that the supporting details option is grayed-out/disabled if you have selected standard deduction previously. Typically when I do my taxes and I want to find out if it’s worthwhile to itemize, I proceed as if I plan to do so, and it may be the case that it is programmed into the software wherein you cannot add any details if the software “knows” that you were planning to take standard deductions. In previous years when I had very high deductions from medical expenses, etc. it was always worth while to itemize and I always like to put in supporting details for my own benefit when I went back to review. It used to be simple because each box allowed a simple right click to select the details option. Now clicking on edit and going through other screens is not user-friendly. In any case, once again, I did the standard deduction in the end, submitted both federal and state a month ahead and got both accepted within three and five hours, respectively.
