Retirement tax questions

I understand tier 1 and tier 2, my question would be I've worked for the railroad for the entire year but I my put the numbers in and TurboTax says my employer overpaid, and I have to contact them is this possible? not only do I have the tier-1 and tier-2 but I also have the federal withholding In box number 2 is that normal could it be the problem?

I went out and check the percentages for the withholdings and they seem correct but TurboTax keeps saying I overpaid and I have to contact my employer