Thank you so much! I was having the same problem when working now on my 2021 taxes - a couple of the medical expense categories had a pre-filled $0 in the box that I could not change - was getting very frustrated until I found your reply to the poster's prior question. Your fix of double clicking to open supporting documentation sheet worked -- I just edited the supporting documentation sheet as I saw fit and then the correct number showed in the box for that medical expense category. Seems like this is something that TurboTax should fix as it certainly is not intuitive as to what you need to do. Thanks again!
