Linux Mint, bad window display
I'm using latest Teamviewer (and this has gone on for several versions) on Linux Mint v19, using Cinnamon Mint (this also occurs with Mint XFCE). The Teamviewer app windows fail to properly go to background when either other Teamviewer windows or other Linux app windows are brought to foreground (they 'collide' where both windows overwrite each other). I cannot minimize any Teamviewer window - it simply lops the title bar off and leaves the rest and continues to prevent any other apps' window to gain the foreground.
This appears to be a bug, because other app's windows properly go to background when Teamviewer isn't running.