Minecraft: Doesn't Load The Terrain And The Blocks And The Sound Have Lag

Hello, good afternoon, days or nights, in this latest update 1.16.101 I have had several problems, the first is that the worlds take a long time to load, and in 1.16.100 that did not happen, the following is that in the parts that no terrain generated, terrain is not generated, blocks stay in place 2 seconds after being destroyed and that's it, please fix it, thank you very much