I earn 1/10 of my spouse’s income, when I add my W2 into the tax return our owing to the IRS go from $500 to $6000, why?

We file as joint, this year I enter on the Tax return software my spouse’s W2 first and it said we owe $500, but then I enter mine and it went up to owing $6000! I earn 1/10th of his income and I get federal and state taxes retain on my paychecks, I work for the city and they don’t retain Social Security, but for $28K I don’t think I should get to pay $5500 extra, what can be wrong there?