The game renderer/chunk culler is treating fully un-generated chunks (along their whole height) as occluders of other chunks. This causes a lot of flickering when flying in creative towards a direction due to leaving the generated area but then re-entering it when the chunk you are in generated.

I believe this also causes the rendering issue where a non-generated chunk is hiding a stripe of chunks behind causing stripes of terrain not to be rendered. This issue is seen in the last screenshot where I am standing in front of a non generated chunk but a stripe of chunks is culled behind. Moving around the ungenerated chunk reveals the culled chunks