Note: This is NOT a duplicate of MC-157812. This is a bug independent of that report, caused by different circumstances and mechanics. (Not caused by the spectatorsGenerateChunks gamerule.)

Issue: When spectating another player/entity's POV, if that player/entity travels further than the chunks rendered at the point the spectating started, and further chunks will not be rendered until exiting the player/entity being spectated.

Expected Outcome: It is expected that all chunks continue to render as normal whilst spectating another player/entity.

Steps to Reproduce:
1. Enter Spectator Mode and begin spectating a player/entity
(Note: Easier to reproduce using two players.)
2. Have that player/entity travel further than the render distance of the spectating player
(i.e. If the spectating player has a render distance of 10, have the player/entity being spectated move more than 10 chunks (160 blocks) away.
3. Watch as chunks fail to render.

Reason for Bug: This issue occurs due to the way that Minecraft handles spectating another player/entity. When you spectate a player/entity, only your camera is attached. Your character is left in the spot where you first began spectating the other player/entity. When you disengage, your character is then teleported to where you stopped spectating the other player/entity. This can be seen by using a client-side mod with Freecam abilities (like Tweakeroo, for example). If you enable Freecam mode whilst still spectating another player/entity, you will see your account is still where that spectating process first began.