The same thing happened to me when I tried to amend my 2019 return. I imported my information and Poof! the Feds owed me $512 without my having made any changes. The imported document showed the wrong Adjusted gross income. It was also wrong about my Tax Liability and anything else that derived from those two numbers. The only way I got the program to work was to switch to forms and fill out the 1040x column A amounts myself. Then I made the adjustments to my income that were necessary for the amended return. It probably would have been easier for me to do it all on paper. I reported my problems with the program in October but heard nothing. Good luck.
