Kerbal Space Program

KSP 1.3.1, KSP 1.4.0, KSP 1.5.1, KSP 1.6.1

Description
When setting the resolution to full screen (and applying) and then unsetting the full screen (and applying)
KSP will stretch the screen out to the borders of the desktop and pixelate everything.

Two consequences of this:
1. Mouse Pointer doesnt work when clicking on the actual buttons on the screen, but will if the mouse pointer isnt on the right spot
after a bit of a search

2. When KSP is pixelated and I drag the KSP screen via the top bar, the resolution in the windowed version will switch to
the same as the current resolution I have set the screen to in Windows 10 (doesnt happen in 1.3.1)

Work Around:
1. When it pixelates Press Alt-Enter and it will force it back to full screen but every time the resolution changes after this
it will pixelate again.
2. Alt F4 then restart KSP will put it back into a windowed state at the set resolution

Proof as follows:
A screenshot or using the Windows 10 game video creation (Windows Key + G) wont show up this
problem so I used OBS to record any videos.

1. How it is in 1.3.1 (Works as intended)
https://youtu.be/pEL5spY0EOE

2. Note this issue started in 1.4.0.

3. How it is in 1.6.1
https://youtu.be/s3HLFQS0U-M
Note I used Alt-Enter to change to full screen before changing again.

4. This is the dragging of the KSP window and the resolution changing to the resolution that has been set via Windows 10
only AFTER the stretching and pixelation
https://youtu.be/UjzGOYULF6o

Additional Information:
What concerns me about this bug the most is that sometimes this happens on the start of a clean install
so if someone buys KSP for the first time and this happens they are going to have problems with clicking
on buttons + be wondering why its pixelated and not know that Alt Tab is an option, or that restarting will fix it.