Question PC restarting after shutdown - GPU/MB problem

[Musti26]

I bought PC 1 week ago, I build it by myself. I tried every solution from Windows settings to restart CMOS, changing power supply. I've installed newest drivers to motherboard and my GPU. Nothing helped. I changed the GPU to old gpu and wow, PC turned off.
Gigabyte B560M D3H
Intel Core i5-10400
MSI Radeon RX 6600 mech 2X 8gb
What should i do? Should I complain the GPU in the store?

 

[Ralston18]

With the new GPU installed boot the PC and try shutting down again.

After two or three restarts (where the PC did not shut down) open Reliability History and take a look at any errors, warnings, or even informational events that may have been captured.

Then reinstall the old GPU changing nothing else. Conduct two or three shutdowns where the PC successfully turned off.

Look in Reliability History again. Do you see anything different between new and old GPU?

 

[Musti26]

@Ralston18
No difference 🙁

 

[Ralston18]

First try the old GPU in another known working computer.

Then try the new GPU in the same computer.

Determine if the problem re-occurs/continues. If so, then return the new GPU.

 

[--SID--]

I bought PC 1 week ago, I build it by myself. I tried every solution from Windows settings to restart CMOS, changing power supply. I've installed newest drivers to motherboard and my GPU. Nothing helped. I changed the GPU to old gpu and wow, PC turned off.
Gigabyte B560M D3H
Intel Core i5-10400
MSI Radeon RX 6600 mech 2X 8gb
What should i do? Should I complain the GPU in the store?

Brand and model PSU?
Brand and model RAM?
Version of the motherboard BIOS?

 

[Musti26]

Brand and model PSU?
Brand and model RAM?
Version of the motherboard BIOS?

PSU is SilentiumP Vero L3 500W 80 Plus Bronze
RAM is G. SKILL 16GB (2x8GB) 3200MHz CL16 Aegis
BIOS version is F7 (11/03/2021)