Starting with 1.18 snapshots, clouds were raised up to y=192, making them do not render properly at certain distances, generating without any smoothness.
Clouds stop rendering before fog starts.
Clouds generate as far as the fog starts.
MC-162713 Clouds don't render far enough on higher render distances; generated with offset to east and south
MC-257532 Clouds don't fill the sky after 1.18 height change