UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.186 Safari/537.36

Steps to reproduce the problem:
1. Open https://hangouts.google.com/
2. Start a lonely VIdeochat
3. Share your screen

What is the expected behavior?
Option to select one of the screens or all

What went wrong?
Screenshare captures all screens at once, although it should allow selecting a screen.

Did this work before? No 

Chrome version: 64.0.3282.186  Channel: stable
OS Version: 4.15.0-5.1-liquorix-amd64
Flash Version: Pepperflash 28.0.0.161

Desktop: KDE
XOrg XServer version: 1:7.7+13ubuntu3
Graphics: NVIDIA
Graphics driver: NVIDIA propietary drivers from https://launchpad.net/~graphics-drivers/+archive/ubuntu/ppa
Graphics driver version: 390.25-0ubuntu0~gpu16.04.1

Issue persists on different driver-versions.