KDDockWidgets draw a strang rectangle.

[mrviit]

I'm learning this library. So I forked here for updating the example code (https://github.com/mrviit/KDDockWidgets). I also update the code changes for this issue (2.1...mrviit:KDDockWidgets:2.1). The result app draw a strange rectangle that I want to change/disable as below image:

I'm trying to debug to change/disable this rectangle but no hope. Can you help me?

[iamsergio]

Hi, try using https://github.com/KDAB/GammaRay and see which QWidget is doing this