I suggest you ask a friend with an Nvidia GPU to help you out and see what happens if you attempt to install an Nvidia card on your PC.
I have AMD and Nvidia cards, and that debug test is very useful since so far it solves 100% of problems for me.
I am not sure if you tried setting your PCIe_16 slot to PCIe 2.0 speed yet in Motherboard BIOS?
Other than that I am ~ out of ideas.
Looks like AMD have messed up Drivers yet again or MSI have messed up their Navi cards again.
MSI were putting tiny thermal pads on the RXZ5700XT models which were causing cards to overheat and shutdown.
They did not do a product recall as far as I know.
If I were you I would just point the seller to this web page, tell them we have tried everything, and ask for your money back.
If you are going to try for an RX5600XT again, go for one from PowerColor or Sapphire as they are the only AMD AIB partners that consistently do a good job since RX Vega launch. Avoid ASUS, Gigabyte, XFX and MSI for Navi cards. They completely messed up.
Could you please update the system soecifications with the exact Windows Version reported by winver?
Currently you have posted this: Operating System & Version: Windows 10 latest version
I am going to try updating a copy of windows from 19.09 and I will test some of those drivers you mention on a new AMD GPU later this week.
I just want to make sure I test exactly the same Windows 10 build,
Best of luck with getting a working GPU.
Bye for today.
I have just ordered a replacement. Fingers crossed this one will work. I
dont have another system to test the GPU with, however it was working fine
minutes before I upgraded to x570 from b450.