That's exactly the problem. For some reason I have no idea of the screen gets blurred and the resize and move notification pops up. Usually reboot to clear it up
you're triggering the resize/move option, which pops up clear in the foreground while blurring the current background. like pressing the power button to give you the power/reboot options; notice the foreground is clear while the background is blurred.
does it happen only on this particular app or on multiple apps?