Hey I have this really strange issue.
I just bought a new laptop with a Ryzen 5 2500U & Radeon Vega 8. Upon factory settings, the border was centered and I was able to make the screen stretched. But after updating the radeon software to 19.9.2 I wasn't able to make the stretched and the 4:3 border isn't centered. I've tried restarting the laptop but nothing seems to be working.
I'm having the exact same issue. It's happening with any non-native resolution. I want to play 1280x1024 or any 4:3 resolution but it ends up staying in it's resolution in the top-left corner. When flipping GPU scaling twice in the Radeon settings, it stretches but it looks god awful. The blur is so unnecessary.