I just got 2 new t-stats. They are the johnson controls model A419.

I've noticed a weird thing about them. They both refuse to display 83F as the current temperature. They always jump from 82F to 84F., or from 84F to 82F. Other than that, it seems to go smoothly up & down by 1 degree increments.

Is this normal? Should I be concerned that these units are defective?