conditional formating - strange behavior

I have a calculated column that just takes the difference of today's data and another date.   The output of which is the number of days shown in the 2nd column below.    I have a divergent conditional format applied, but for some reason, I get different colors even when the values are exactly the same  (and the respective dates are also the same).  

And the conditional color does not seem to apply consistently down the data series.   You can see below that the 58 is blue, then a dark red 54...followed by a dark blue 54...then another dark red 54, etc.... 

Any idea why this is happening?