Game Seemingly Reverts to Windowed Mode when Tabbed Out

[DarknessNightshade]

I've noticed a few times where when alt-tabbing or leaving my desktop to lock itself seems to make the game change itself into Windowed mode with altered graphical settings, sometimes higher/lower resolution, GPU particle settings, and occasionally messing with my desktop graphics settings and forcing me to have to go back into my desktop settings to revert the changes.

I've been able to reproduce this twice recently, by alt-tabbing so I change what tune I'm listening to while I'm grinding on YouTube, or just leaving the desktop alone so the automatic timed lock kicks in. 

I've tried a couple things to remedy this:

- Windows 10 has a setting to change the scaling of the desktop, this has always been set to 100%

- Advanced scaling settings have been turned off as Windows apparently has a setting that auto-scales apps to "not look blurry"

- Set Warframe as a preference for graphics performance

- Setting warframe's own Windowed/Fullscreen graphics settings back to Fullscreen, and reverting whatever random changes seem to have occured. 

Though, this problem seems to re-occur semi-frequently, just today I had to restart my computer as closing the game (that was still running after an Alt-F4 attempt in a Dojo) with Task Manager didn't seem to revert the desktop to normal.