Question GPU Artifacts/Flickering & System Crashes - - - not sure if it's GPU or PSU problem ?

[ChardBurger]

Hi there! I am a beginner builder and just built my first computer last January this year and I'm currently having a problem with my rig and I am not sure what to point at.
It all started in July 5 when I've turned on my computer after coming home from work, the motherboard light just lit up steady white with no boot and no monitor signal.
So I did the following:

• Cleaned the rig
• Re-slotted the GPU to the second PCIe and also it's power connectors

(NOTE: I updated a bunch of drivers with Armoury Crate, AMD Adrenaline update, and Windows updates the day before the problems happened)

This also popped up once even though my PC was working fine for a while until the reboots started. (This screen never popped back up after the below)

I don't remember much after that since everything kinda worked for a while until I noticed that I'm starting having awful lags and also getting random system crashes when I play Cyberpunk and I get to move my camera a lot. It even crashes even for playing Project Zomboid and moving the camera around these times. Apparently I just learned that the second PCIe is weaker than the first, the more I get to know.

After this happens, I decided to reformat my PC since I thought it might be the system updates and it might have corrupted some system stuff, so I've thought.

Cleaned the whole PC, re-slotting everything (to where it should be) but the mobo, procie, and PSU, I've reformatted the PC and installed all the latest drivers for it and downloading 3DMark and Cyberpunk 2077 for testing.

Everything went smoothly and I'm starting to get my old performance back. The days went on with my benchmarking with 3DMark (Stress Testing mostly) everyday to see if the problem pops up.

Long story short, it did and still does it to this day.

Problem I've noticed:

1. PC REBOOTS WHEN GPU IS GETTING UTILIZED
   • Sometimes I get a system crash when I hit a certain point in the 3DMark GPU benchmark or while playing a game (Cyberpunk 2077--Custom High Settings)
   • I'll know when it will reboot when my screen flickers and the utilization of the GPU continues unless stopped (i.e ending a 3DMark Benchmark session)
   • VIDEOS FOR REFERENCE:
     • FOOTAGE OF SYSTEM REBOOTING AFTER DISPLAY FLICKERING/GPU ARTIFACTING WHILE DOING BENCHMARK
     • FOOTAGE OF DISPLAY FLICKERING/GPU ARTIFACTING WHILE BENCHMARK BUT NO REBOOT
2. DISPLAY WILL FLICKER BEFORE IT REBOOTS/CRASH THE SYSTEM
3. FLICKERING IS MORE APPARENT WHEN I USE AMD ADRENALINE DRIVERS V. 23.7.1 (LATEST)
   • Current using 23.5.2 (Version before the problems)
   • Note: I still encounter these flickering and crashes even though I rolled back but GPU is more stable with this driver version
4. APPS THAT I'VE USED THAT SHOWED SOMETHING NOTABLE
   • Cyberpunk 2077 - Display Flickers and System Reboots (Frequent--kinda renders the game unplayable)
   • Project Zomboid - Display Flickers and System Reboots
   • Wallpaper Engine - Display Flickers and System Reboots (Problem stopped after clean installing AMD drivers again)
   • Google Chrome: Youtube - Showed GPU Artifacts once while watching video
   • 3DMark (Speedway) - Display Flickers, GPU Artifacts after stress test, and System Reboots

Should I get this looked? Not sure if it's my GPU failing me or my 650w PSU not giving me the power I needed.
I am planning to use my GPU Warranty but I wanted to see if I can do something about this first before I return it since I got this online from somewhere far and don't want to sacrifice weeks not using my PC.
Also planning to get the whole pc checked locally. Any tips and advice you can give me? Please let me know. Getting bumbed out after doing everything I already know and I'm scared that it's a hardware problem since I can't afford to get another GPU..

Full Build Details:
CPU: AMD Ryzen 5 5600X
CPU COOLER: Deepcool AK620
GPU: XFX AMD Radeon RX 6600 XT
MOBO: ROG STRIX B550-A GAMING
RAM: 2x16GB G. Skill Trident Z Neo 3600Mhz CL18
SSD: Samsung 970 Evo Plus 1TB NVMe PCIe
HDD: Seagate Barracuda Compute 3.5" 1TB
PSU: Be Quiet! Pure Power 11 FM 650W

Plugged in a UPS? YES -- AWP Aide Pro LCD 600W-1000VA UPS
Monitor: ASUS TUF 27" VG27A @ 144hz (Using HDMI cable)
Fans? 6 aRGB fans
Airflow? PC Case has good airflow as far as I know
PSU Extension Cables? YES
OVERCLOCKING WHEN OR BEFORE THE PROBLEMS HAPPENED? NO -- I was running stock configs for everything on and before July 5 but have dabbled lightly with overclocking
BSOD? NO
PC USABLE? Yes but when I game, there's a high chance of not having consistent performance and might crash
OVERHEATING GPU? I don't think so. Highest temps I've seen while gaming is at 50 - 60 degrees
TRIED THE GPU ON ANOTHER SYSTEM? No, not yet. Though I am planning to this weekend

 

[ChardBurger]

New footage taken right now having a stress test
- display flickers, waiting for it to crash but I just ended the stress test after the 2nd half of the loop

 

[ChardBurger]

Update: PC is still usable but the flickering still persists specially when the PCs used for a long time. I haven't experienced crashing so far too, just the occasional screen flickering and I also noticed that even my stream with Discord flickers too since my mates noticed.