As I traveled through the End Gateway on my 4 trip. I explored the End a little bit, generating new chunks as I did so the small Islands started to generate in an odd way. Forming half islands and in grid patterns, this doesn't occur when over the large island masses though. I tried a couple other worlds and this seem to occured a bit.

EDIT:
After travelling for bit. I reloaded the world and got stuck unable to move. So I quickly /kill @e After doing so the islands just vanished. I think it's a client side thing that's happening