charged creepers spawning instead of normal creepers

My friend created a new world, they are also experiencing the problem. There have been no thunderstorms, and charged creepers have been spawning frequently, but no normal creepers have spawned. The first time we played on this world was a few days ago, and that was when we noticed the problem. When I was blown up by one, the death message said blown up by creeper. Unsure if this is just a texture issue or if they’re actually charged.