I'm not an accountant, but I do some trouble shooting for math and programming issues. I can't say that my solution is correct from an accounting point of view, but I know it fixed my math problem and I was able get through the error check and file my return.
Working in the Forms view of my K-1, I wanted the same value to appear in both the Regular Tax and QBI columns for 2018. And also in those two fields for 2019. (Different values for each year.) My problem, like yours I think, was that entering the QBI for 2019 changed the QBI for 2018.
Above that on the same form is an entry in Section D2, Letter H, 3a "Previously disallowed losses freed up in the current year" That number was not, but needed to be equal to or greater than the total of the two QBIs for 2018 and 2019. Enter this value before entering the QBI for 2019 below.
Let me know how this works, but don't as my why. 🙂
