This is a chunk rendering error I haven't seen happen before the 1.13 snapshots. It happens consistently in the debug world (see MC-125653), but seeing it in isolation allows one to examine its effects better and proves that debug world fuckery isn't the only culprit for this issue.

A chunk doesn't render. If you are on the same x/z chunk coordinate as that chunk, chunks behind it (relative to the player) don't render. If you are inside the chunk, behavior might be slightly different (depending on camera angle), but I now realize I didn't test sufficiently while recording the video. F3+A typically fixes the issue.

See attached video for a short demonstration.