Recently I've been having a bad time with frame stuttering (as can be seen here). Usually restarting the game fixes it, but today it didn't. Just to note, I am only getting the stutters in missions, not in my orbiter. Here's a list of things I've tried (that haven't worked):
Verifying and optimizing game files (did work once, but not anymore)
Clearing nvidia shader cache
Setting all video settings as low as possible
Deleting settings config file
Reinstalling WF
Running antivirus scan, malwarebytes to be specific
Disabling all non-microsoft services in msconfig and restarting PC
Reset video driver settings
Reverted to previous video driver version (and updated again because it didn't fix anything)
Then I tried launching a mission by esc>navigation instead of pressing 'X' on navigation and the stutters are completely gone. If I back out of the mission and try again by pressing 'X' the stutters are back again. No idea what would cause this and I guess I do have a fix for my problem, but it would be nice if I didn't have to use this workaround.