Box 18, 19, and 20

[jinamarie31]

I have different values in box 18 and 19 on the different sections at the bottom of my city or local reference copy of my W2 and box 20 is the same locality. Turbotax said I've entered an error and wants me to delete one of the entries bc there should only be one entry per locality. Can you explain this or could it be an error? Thanks