While flying through blocks, occasionally, a side of a chunk is visible in spectator mode. Only one side is visible. Problem is fixed upon relog.

The first and fourth screenshots are examples of the problem. The second shows that it is not visible from the opposite side. The third one is after a relog from the first angle, showing that the error has disappeared. Notice, in the fifth and sixth screenshots, the red square that shows that it is the edge of a chunk.