World Spawn Chunks inactivity

The Chunk arround the world spawn area arean't load.

When I create a new world and start to build some machines and farms at the world spawn, the chunks arround supose to be always loaded, but in my case is not.

If you want to test it:

-create a New World
-then you can plant some seeds (don't forget to make sure the farmland is irrigated)
-teleport yourself farway enough
-use the command: /gamemrule randomtickspeed 9999
-wait a couple of second and get the randomtickspeed to 3
-finally teleport back to your farm see what is the result. (for me, my weath haven't grow.)