UserAgent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:50.0) Gecko/20100101 Firefox/50.0

Steps to reproduce the problem:
1. Open Chromium
2. Open another window
3. Try to alt tab away from Chromium

What is the expected behavior?
To successfully switch to another window when alt-tabbing

What went wrong?
It didn't switch to the other window

Did this work before? N/A 

Chrome version: 55.0.2883.87 (Developer Build) Built on Ubuntu , running on Ubuntu 16.04 (64-bit)  Channel: stable
OS Version: 4.4.0-51-generic
Flash Version: 

There are absolutely no solutions to this issue, I've searched everywhere and wherever this error is reported, there're just posts, and more posts of users experiencing this same issue with absolutely no help from anyone. Seems nobody's able to diagnose or fix this.

Video below,
https://youtu.be/YRmG8oqGXk0