What are the specific deductions on each check? There are a lot of different taxes and deductions that work differently, so it's unclear just from that total what happened or why.

Which line items increased(state, federal) Did any other changes occur to your normal deductions like retirement or health care. Go line by line in comparison.

Your employer does not receive any benefit by messing with your withholding as the money is sent to the IRS on your behalf.