i am thinking it is to do with the UmaxSkinDecalsPerActor and UMaxSkinDecals values (assuming the image between both profiles are your profiles) <-- because the op mentioned that visual defect only happens in combat, which i would assume would be the actors causing that visual defect.
so it depends if you are getting the same visual defect on actors.
Reset these UmaxSkinDecalsPerActor and UMaxSkinDecals values back to Default First, then if the artifacting still occurs after doing that, then check out the Spoiler.
screen tearing has absolutely nothing to do with the issue at hand. that image you posted above this, is also a form of artificating.
Artifacting has many Visuals, such as polygons, rainbow colours, black lines (which can cover a variying amount of the screen, from covering the full screen to covering parts of the screen, depending on the severity of the Artifacting.), etc etc. Simply put it is Visual Corruption, that has many possible visual looks (for lack of a better statement) Artifacting has a very high chance of being caused by unstable hardware (Primarily the GPU) which as mentioned can be caused by all sorts GPU based issues, such as hardware failure (Hardware that is on its way out), unstable overclocks, too much voltage, overheating, incorrectly seated GPU, Faulty Vram, and the list goes on.
however Artifacting can also be caused by Corrupted Textures, Meshes. (it is not exclusively a Hardware Issue, it just has a much higher chance of happening, If Hardware Based)
Screen tearing is literally a horizontal line that goes straight across the screen, whenever you move their is tearing, it is only visible when you move the camera. <-- that is what screen tearing is.
if you dont move the camera at all (meaning you leave the mouse and keyboard completely alone, their will be no screen tearing at all, until you move the camera again. it is a motion based visual defect, that will always be visible as a very thin horizontal line, that typically sits in the dead center of the screen, but can move up and down the screen.
Artifacting on the other hand can be a lot of different visual defects. such as the image you posted directly above this post, and also the primary image on op post.
Note: Artifacting = Visual Artifacts