Hot damn, I thought this was a mod problem and spent all day trying to solve it... The only reason I noticed it was when using vanilla blood decals last longer... but apparently this is a vanilla bug that was never fixed? It's a bit hard to see in the image but in game it's very noticeable line cut in half like half the decal is missing on his upper chest.
CD Project Red removed blood decals on Geralt rather than fixing them in an official patch... mods can re-add the decals, but they'll still be broken.