The bug

Chunk positions of entities are not updated when they are moved to another chunk by /teleport, /data modify or /execute store until entity ticking.

Steps to reproduce

1. /summon minecraft:armor_stand 0 0 0 {UUIDMost: 0L, UUIDLeast: 0L, Marker: true}

2. /teleport 0-0-0-0-0 1000000 0 0

3. Reopen the world.
   The following warning message is printed, and the level fails to load the entity. 

   Wrong location! (62500, 0) should be (0, 0), avh['Armor Stand'/5, l='world', x=1000000.50, y=0.00, z=0.50]

    

Code analysis

net.minecraft.server.level.ServerLevel#updateChunkPos should be called to update entities among entity sections, but it's not called in the above commands. Entities moved to another chunk will not be re-added to the proper entity section until ServerLevel#tickNonPassenger that includes updateChunkPos is called.
In the reproduction steps, the entity teleported to the chunk [62500, 0] has Pos=[1000000.5d, 0.0d, 0.5d], but it's still in the chunk [0, 0] since the chunk [62500, 0] is not an entity ticking chunk. This inconsistency causes the failure on entity loading.

Comparison with /spreadplayers

No inconsistency occurs in /spreadplayers since it calls Entity#teleportToWithTicket on success. Entity#teleportToWithTicket adds a region ticket with level 0, updates tickets, and then calls Entity#teleportTo that includes ServerLevel#updateChunkPos.

Possible solutions

• Load the destination chunk.
• Throw an exception and don't move the target entities if the destination chunk is not loaded.