Strange behaviour with Steam window

[mBeratarvide]

Describe the bug
The drop-down interface that appears only when you drag a window also appears when you click on the top part of the Steam window.

To Reproduce
Steps to reproduce the behavior:

1. Open Steam
2. Click (and hold click) on top part of the window
3. Then the layouts show without moving the window

Screenshots

Information (please complete the following):

• Tiling Shell version: 17.3
• GNOME version: 48.7.