Line density visualization

[AnnaScholl]

Hi everyone. 

Could someone explain why this might be visualized this way? I've run the line density tool, and I understood (I think) all the parameters, but I'm confused as to why visualizing the result in 5-class Jenks would give me this light purple square. The radius was 8 meters, and the square is way further than most lines. To compare, attached is an image with 5-class jenks on the left and the stretch viz on the right. Just want to understand how/why the rectangle is there. That is also my environment for the analysis, so it's from that, but why?

Thanks!

[AnnaScholl]

Still hoping for an answer!