I was unable to find this myself, but entering these chunks made them invisible and caused a lot of strange chunk loading and unloading. Punching a block in some of the chunks made them load, but the main chunk(s) where the geode was located were impossible to enter (they kept pushing me back).
Can confirm there's something very broken with this area, at least.
The snapshot you're on isn't 21w14a, it was 19w03a. Link to the bug in question: MC-140950