This bug seems to have shown up for me. Went into "windows display settings" (search from start menu) and set the "scale and layout" to 100%

Then went into xchange editor
File --> Preferences --> General --> UI Scaling --> and selected "No Scale (System DPI)

Rebooted computer.

Now it works.

My screen grab software isn't working, but I'm here to confirm that this bug is back. I'm on a 4k monitor run from a GTX1060 with Windows 10.

Let me know if there is any additional info I can provide to help you run this bug into the ground.

I really rely on this software for my work...