Hello,
Here are the details of the 4 problems:
1-The slime blocks I see for the first time without me having put them down (like on ex servers) don't have the full texture when I see them and a few seconds later I see them normally.
2-The underwater plants and bubbles replace the water texture with their texture.
3-Blocks that I place appear a few seconds later and the same thing for blocks that I break.
4-When I launch a world and it tells me "here we go" a big black band appears on the game image.
Thank you very much