Suitability Model Transformation Plot doesn't make sense

[MiniR]

I am using the suitability modeler and transforming a slope raster (15 meter baseline).

I would assume that a slope of 0 would be the most suitable and then the suitability would decrease from there, but the histogram does not represent that.

The function line makes sense to me, but when I hover over the histogram bars the suitability value does not make sense.

Am I understanding the plots wrong or how can i fix it so that the slope starts from most suitable at 0 and then decays from there?

Thanks

In these side by side comparisons the histogram says that a higher slope value has a higher suitability value than slope values 0-4