I am amending a return I did not originally prepare. I entered the information and it matched the original return. Iowa tax was $825 on line 39 as expected per the original return and the Iowa tax tables.
I checked the box to amend Iowa (and did nothing else) and the tax changed to $2035. Uncheck the box and it is back to $825.
I'll probably end up doing by hand but thought I would put this out here.