Artifacts on absolutely new PC

[Beeswitt]

Hello everyone!

I built a new computer for my friend with completely new components, it easily passed stress tests in 3dmark, furmark, aida64 and occt. I tested it for more than 10 hours. I made sure it was working without any problems and took the computer to my friend. He was using it for about 3 days, and at one point artifacts appeared on his desktop, he turned the display off and on, the artifacts disappeared, after 10 minutes they appeared again, he turned everything off, reconnected all the cables and turned it on again, after this the artifacts have not recurred yet in two days.

PC:
GPU: MSI RTX 4080 Super Gaming X Slim (Latest Drivers)
CPU: AMD Ryzen 7 7800X3D
MoBo: MSI X670E Tomahawk WiFi (BIOS - 7E12v19)
RAM: Kingston DDR5 6400Mhz 2x16Gb
SSD: 2x Samsung 990 Pro 1Tb
PSU: Be Quiet! Straight Power 12 1000W
Cooler: Be Quiet! Dark Rock Elite
OS: Windows 11 Pro, (Latest Updates)

Display: BenQ Zowie XL2566K (360Hz)

Maybe you have some ideas about what is wrong with this PC or its just one-time glitch that never gonna repeat?
And how to be sure, which component is faulty? Display, or GPU, or something else.
Maybe you can recommend some software to troubleshoot this artifacts?

[SkilledRebuilds]

Wiggle the Display Cable/s,....

 

When he plugs the display cables in, turn the PC on, get to windows..(Driver loaded)., give the cable a wiggle, see if it creates the artifact.

If so,... Replace his display cables.

I've seen this with a cable that I thought was A-OK but wasn't, stressed about it, but prior to replacing anything, I test cables and what do ya know, a little wiggle instigated the artifacting off and on with certain wiggles. (Could be the port or the cable) but just make the user aware of such things.

Lazy personalities would just leave it and re-wiggle every now n then.. but replacing it would be advised.