Terrain Appeared/Disappeared randomly in my world

I loaded my Minecraft world to check if there was something wrong with a button on my keyboard (and there was). I fixed the problem with my keyboard and loaded my world again only to find out that a chunk of land had moved directly in front of my house, on top of existing terrain. I decided to explore around my area and random chunks of land had either appeared or disappeared all across my world. Some of the chunks of flatland in the distance of my world had even turned into an ocean!

I have no idea what happened so I do not know how to recreate this. This world was only made a few days ago in 1.14.3.