Wow no one here is able to answer and yet the problem turned out to be so simple after spending so many hours looking through the internet.
The reason why my landscape scene disappear when rendering is because I didn’t increase the Loading Range which can be found in WorldSetting after opening from Window Menu and then under “World Partition Setup” subsection go to Runtime Setting>>Grid>>Index>>Loading Range.
I hope I saved the trouble for everyone who comes with the same issue that I had to go through 