This the latest from AMD for your GPU card (03/05/2020): https://www.amd.com/en/support/graphics/amd-radeon-r9-series/amd-radeon-r9-200-series/amd-radeon-r9-...
Here is Cnet Specs on your GPU: XFX Radeon R9 270X - Double Dissipation Edition - graphics card - Radeon R9 270X - 2 GB Specs - CNET
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Your GPU may not qualify for running today's DirectX 12 games by the above description.
You can always Stress test your GPU card to see if it passes without any artifacts or overheating. Furmark Fuzzy Donut suppose to be good at finding out if your GPU card develops Artifacts while under stress. But it puts a huge amount of stress on the GPU card while testing. Or you can try using OCCT which checks your CPU, GPU, & PSU.
Overheating is one of the main reasons for a GPU card to develop artifacts besides Overclocking it or defective vRAM Memory.
This gaming website gives you all the hardware requirements you need to have to run various games: https://www.game-debate.com/games/index.php?g_id=5064&game=Steam&systemCheck
By the way, I don't believe Windows version 1909 is your problem. Good chance your GPU card is going bad.
If you want to upgrade you need to be sure you have a powerful enough PSU to run the new GPU card. You can use this website as a reference for the minimum PSU you need for various GPU card: PSU REQUIREMENTS - RealHardTechX