Hey, Greg.
My problem is completely gone. And I think this has something to do with the latest Windows Insider build (posted mine on the last reply).
You said one of your pcs has the problem and the other don't. Maybe one of them is with the windows insider updates and the other is only with the regular updates. Check it out, please.
If someone out of the Insider program and without the Creators update isn't having this problem, then this probably has nothing to do with Windows itself. And maybe really it's a Steam related problem or something else.
Thanks for your time and input everyone!