Please take a look at the picture!
On the first two images Smartgit latest version 18.2.3 #13220. On the third image of PlayOnLinux 4.2.12. I ask you to correct this behavior of windows
That's a known bug that may be out of the scope of elementary. Anyway the fix is to run the app with
GTK_CSD=0. You can do this from the command line:
And you can also modify the .desktop file so that it works automatically when you open the app. You just need to find the line starting with
Exec= and add
env GTK_CSD=0 to it so it looks like
Exec=env GTK_CSD=0 /path/to/playonlinux