Window level and width reset issue in vtkresliceimageviewer

I have made the MPR application based on the fourpaneviewer and I can manage the window level and width using the left mouse. For example when I changing the window level and width over the axial viewer by using the mouse and when I turns into negative the width(or both window level and width as negative), and clicking the reset window level and width button it turns into binary format… even the window level and width value shows as positive.

Here I attaching those images:

Normal Window level and width

image

After adjusting into negative values

image

After resetting the value

image

How can I resolve this issue. I’m currently using VTK 8.2.