Which tax software did you use?
You got it. That is the issue for you. For purposes of Homestead rebate, household income includes:
"Household income" includes certain nontaxable income such as social security and SSI benefits, pensions and annuities, unemployment compensation, capital gains, contributions to IRAs and Keogh, SEP, SIMPLE, and deferred compensation plans, court ordered spousal assistance, etc.
There may have been an error in the tax return as prepared by tax act. YOu may want to do a manual return to be sure. This is the main publication that covers the Wisconsin Rebate program.
It has worksheets you can use to find out where the program went wrong, if at all.