Chunks change and move throughout world saving

This occurred on a super flat world of bedrock and grey concrete powder. The first save was fine but, when I loaded it up again the outer edges of the render distance from there on out were chunks of white concrete powder. From then, every day brought a new messed-up world with error blocks appearing, and parts of my builds moved by the chunks. I have pictures for reference. By far the largest glitch in my Minecraft years. (Sorry for the quality)