Density Plot I don't understand?

I’m reading a sample machine learning auto-generated report at https://app.jadbio.com/share/e18eafb5-ba15-4743-925c-2e3b3fe6bbbb.

In the bottom of the page, I see:

I don’t think I understand the plot.

• For the Bladder blue group, they are true positives. I would expect the density is high for the blue group near 1.0. But the report shows very low density for the blue group near the 1.0 end.