Not every build will be as stable as the last you played, just a simple fact when creating a game. Something they've changed or added is making your setup have a stroke. Be kinda hard to diagnose a fix when the first most obvious issue is simply the age of your hardware.
Just out of curiosity, how many frames do you actually play at even on the lowest setting? I'd be surprised if it went above 15 fps and wasn't constantly choppy.
I'd also finish with simply saying this.
Save up, and buy yourself a decent rig/laptop at least within 2 (edited out 5 as it's still too old imo) years of current year. You will absolutely not be able to play this game when it's fully released. I understand that optimization is obviously a moving target right now, but the games also completely barren. So there will come a time when that rig is no longer able to keep up. You just now hit that threshold by some miracle.
It's not the first Report of this problem and before it was AMD also but not as old as Barts VLIW and actually GCN 7000 (GCN) series if im not unsure
But it is the 2nd time now these artifacts come up with AMD Hardware and in Wild-Life running context specifically.
Though in General Unreal will work better on Nvidia Hardware through their older Generations, but for AMD it's not a given to work on anything before GCN.
Epic started first when the Consoles came out to really optimize for AMD Hardware specifically Paragon was the very first more AMD optimized Engine Build for GCN starting to erradicate lot of Nvidias investments out of the Engine into generic agnostic functioning systems.
Everything pre GCN is pretty much not supported by anyone anymore for AMD you either have luck that it works or at the lowest problem level have to live with artifacts.
Also neither the AMD Driver Teams priority lies within anything then PRE GCN to fix specifically.
Tough in this case of the 7000 Series Southern Island is GCNs first iteration away from the VLIW architecture to Nvidias Scalar approach.
This bug is strange but it seems to play specifically out on the Directx Shader Model Layer and the AMD Compiler.
ekomatik
try to test different drivers pre Adrenalin
GCN was a really big step even bigger then RDNA 2 that is upcoming, pre GCN like your HD 6800 Series, if it works be happy if it doesn't it's like it is.
But this is why i like to keep Wild-Life as a very specific stability test case, compared to other indie Unreal projects
In their overall complexity Wild-Life plays on a very high level and Epics ongoing progress to get the Engine Rock stable on the Next Generation Consoles (RDNA 2) with the Unreal 5 big data refactoring which we see continuing.
Best optimized Low level GCN Engine no doubt = IDTech7 and it runs on Nvidia equally amazing (absolute master class hardware optimization work in which direction Unreal 5 is starting to heading)
For everyone Unreal 4.22 was a very important core Performance refactoring release making room for more additional overhead into the Engine.