Deductions & credits

@EHV   Your 2023 and 2024 are not exactly the same.  You only worked 6 months in 2023 and a full year in 2024 so you 2024 W2 income is twice as much.  You made a lot more income in 2024.  More income = more tax and usually less refund.   Your withholding didn't increase enough to cover the tax due. Or some credits you got are reduced because you made more income.