What I expected to happen was...:
the world load chunks while i'm connecting, or move into the world, or change dimension

What actually happened was...:
When playing alone the world doesn't load  any further chunks when exploring, when playing together with another player the second player don't load any chunk, same as the player change dimension like nether.

Steps to Reproduce:
exploring the world for while.

open the world to the lan or server, and connect the second player after few minutes not immediatly, change dimension