Terrain tiled not loaded when i open the level

Hello to all
i have a problem with unreal engine, i am trying to use tiled terrain.
i created a level, using this tutorial

when once the application is saved and the program closed, I reopen it, I find the level with the land not loaded.

I go to levels and load them and everything is visible again.

I can’t understand why the loaded land doesn’t save me.
Any suggestions?

thanks
Nevarim