OK the fix is this

1a.If you have the config tool mod, idk how to do step 3 on there

1.In your fallout4prefs (C:\Users\tonyh\OneDrive\Documents\My Games\Fallout4) find the lines

bFull Screen=

bBorderless=

bTopMostWindow=

bMaximizeWindow=

iSize W=

iSize H=

Change Them To

bFull Screen=0

bBorderless=1

bTopMostWindow=0

bMaximizeWindow=0

iSize W=1920 (change these to your native resoloution)

iSize H=1080 (change these to your native resoloution)

2.Right click your Fallout.exe (or for some people just Fallout4) and click Properties. From there click the Compatibility tab. From there Make sure Disable display Scaling on high DPI settings is checked. apply that and press ok.

3.make sure your Fallout4Custom.ini says

[Display]

iLocation X=0

iLocation Y=0

4. and that should be it.

Notes

This is caused by what i think is when your computer doesnt meet the requirements for the game. i have this problem all the time and i think i solved it.