Differences in z-score values for the same region, same donor and same probe

I tried looking for z-scores values on Allen brain atlas (on the six healthy brain donors). Does anyone know why z-score values are different when you look at them on the two screen shots?
These values are for the same donor, same region, same gene and same probe. On the upper screen shot z-score is 0,55 and on the other one below is 0,79.

Thank you