1.17 World Generation Beyond Y Level 0

I found this bug after recently switching to 1.17 Experimental Gameplay on my Windows 10 PC. I am not complaining because I just thought this was cool and that someone should know about this. I found a ravine with a chunk error. The entire chunk of the world bottom was raised by about fifty blocks stretching bedrock with it. More clearly explained in the pictures. I was able to walk around at Y Level -63 before a met the standard few-block thick bedrock world border. Also by this bug, there were flat walls of water and lava that would not flow outwards.