Mobs spawn inside tall snow layers, and then can't pathfind

When it snows (at least in some biomes) the snow layers pile up, but at some point, the snow is so tall that monsters (which spawn on top of the opaque block below the snow layers) are stuck inside the snow. They should spawn on top of the snow layers, so they won't get stuck

 

Perhaps related to (java version)?: https://bugs.mojang.com/browse/MC-66587