Snow removed via commands are glitched for clients

I cleared the snow out of a snow biome so I could see clearly, but for some reason, the client still sees snow. Deleting it is only momentary, and rejoining causes it to re-appear.

I'll explain what happened.

I cleared all the snow using

/fill ~-256 50 ~-256 ~256 128 ~256 air 0 replace snow_layer

It works perfectly, but my brother "the client" could still see snow on his end. I don't know if it's probably cache for something, but he joined the world before I cleared all the snow too.

On his end, the snow acts perfectly normal. It's still affected by gravity and everything else.