When you set a spawn point with /spawnpoint, if the block occupying the spawn point block is a bed (in the Overworld) or a respawn anchor (in the Nether), you will not be spawned at the world spawn, instead the game will act like you set your spawn with the bed or respawn anchor and spawn you next to the block. This will only happen if you are using the correct spawn point block for the dimension (it will never happen in the End). The respawn anchor does not need to be charged.

To recreate:

1. Set a spawn point in the Nether or Overworld with /spawnpoint
2. Place a bed if you are in the Overworld or a respawn anchor if you are in the Nether, so that it occupies the spawn point block
3. Die
4. When you respawn you will be next to the bed or respawn anchor instead of being at world spawn