Intermittent Freezing using Alt+Tab(App Switching) in Linux

Reproduction Rate: 70%+

Details: When switching from the game to other apps I have open the game will sometimes freeze up. When this happens, if I just tabbed back into game, then I can't get back to Ubuntu desktop to shut the game down and have to reboot the machine. Sometimes I am able to open System Monitor(like Task Manager in Win), and kill the game.

Steps to Reproduce: Have a few apps open in Ununtu and Alt-Tab from the game to other apps, and back again. Have had this happen with Firefox, and with VLC Player, Gedit, and various other apps.

User Specs:
OS: Linux 4.4 Ubuntu 16.04 64bit
CPU: Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz (4) System RAM: 15992
GPU: AMD Radeon (TM) RX 480 Graphics GPU RAM: 7513
SotA.EarlyAccess.Linux.64.554.Date.02.06.17
Area: Novia
Area Display Name: Novia
Loc: (440.6, 12.5, -307.0)