some lower chunks do not load properly

Every time I enter a world the bottom layer from

 Of the block, less, it is loaded correctly but when exiting and re-entering the game the minor layer is affected and large empty chuncks are generated and this affects the world permanently. I also mention that I only have the experimental option activated, caves and cliffs.

 and I have tried it with several worlds and the same thing happens too, my brother tried it and the same thing happened