I don't know what to do anymore. Screen flickering/glitching and random rebooting in Windows 10

###Build Help:

Hey.

I've been having these problems for a LONG time now, and I've tried everything I can think of to fix it.

Whenever I'm in Windows or trying to install Windows I get terrible screen flickering/glitching and what seems like endless rebooting. I don't know how to best describe the problem, so I made a short video: https://youtu.be/0jZRGq7wFMg.

• Tried swapping cables on just about everything
• Swapped SSDs from a computer that works
• Removed GPU and even tried with a different GPU
• Updated and rolled back BIOS many times
• RMA'd the motherboard, they couldn't replicate the issue
• Tried with different PSU
• Ran MemTest86, no problems

Specs:

• i7-8700K
• ASUS STRIX Z370E
• EVGA 1080 Ti FTW3
• Samsung 850 EVO 1 TB
• EVGA SuperNOVA G3 650W

Please watch the video and tell me what to do. I don't know what to do anymore.

Edit: Well after a whole day of testing it's barely gotten through 2 passes. 1 said it was fine, waiting on this next one to finish. What DID happen though is my CPU cooler broke, so I got that going for me.