This refers to an older report, opened by myself (MC-267795).

This bug was introduced with the 1.20.3 update, and has not been patched since. 

Whenever a player dies in any version, from 1.20.3, upon respawning, there's a "Loading terrain..." screen, being thrown in their face. From what I was told, this has been added to prevent players from falling into the void, whenever a world isn't loading correctly (MC-228420).

However, this screen is being displayed every time a player goes through the process of respawning, even if the spawn chunk is already being loaded.

This can be extremely annoying whilst playing mini-game maps, especially if the gamerule "doImmediateRespawn" and "kill" commands are used a lot.

From my experience, using mods, which most players do nowadays, makes the "Loading terrain..." screen display exponentially longer, depending on the mods in use (Comparison at 60hz: No mods / a few mods).

Expected behaviour:

Loading terrain screen won't be displayed, if involved chunks are already being loaded.

Steps to replicate:

1. Create a new world, set "Allow Commands" to "ON".
2. Open the chat and paste the following commands: 

   /setworldspawn ~ ~ ~ (Sets the default spawnpoint to your current position)
   /gamerule spawnRadius 0 (Prevents you from respawning in nearby chunks)
   /gamerule doImmediateRespawn true (Enables immediate respawning, skipping the death screen)
   /forceload add ~ ~ (Permanently loads the chunk, you're positioned in) 

1. (Step 3, formatting is buggy) Kill your character by opening the chat and pasting: 

   /kill @s 

1. (Step 4, formatting is buggy) Repeat step 3, if you didn't notice the "loading terrain" screen (This might not be as noticable if your monitor uses a higher-end refresh rate).