Hello,
since a very long time when I maximize my TeamSpeak 5 window, an around one pixel wide gap exists between the bottom border and the windows taskbar. I can see my desktop or any other open program through that little spacing.

most recent TS5 version (beta68.1)
Windows 64bit
Monitor: Optix MAG24C 1920x1080
Here with a white-colored program in the background: