It appears that the bed respawn location is tightly linked to the x/z coordinates of the location where the player initially interacts with the bed, even when there are more sensible respawn locations.

Steps to reproduce in the attached world file:

1. In survival mode, stand on the light blue concrete (with the pressure plate), and interact with the bed to set your respawn location
2. Use `/kill @s` to kill the player, and choose to respawn
3. Observe that the player respawns on the light blue concrete (presumably expected, arguably intuitive)
4. Now move off the pressure plate and onto the red concrete (or anywhere else on the map), causing the light blue concrete space to become obstructed by the trapdoor
5. Again use `/kill @s` to kill the player, and choose to respawn
6. Observe that the player respawns on the yellow concrete, far above the bed, instead of on any of the more sensible lime concrete blocks (unexpected? or at least unintuitive){}

Interestingly, if the player is able to actually sleep in the bed, they awake standing on one of the green spaces, but still respawn on the yellow space after dying. You can use `/time set night` and repeat steps 1 & 2 above to observe this behavior.

The ability of a bed to move the player to a new location via sleeping, while simultaneously setting their spawn, is a key component of a survival build I'm working on. However, the respawn behavior I've described here is complicating things. I'd be eager to know of any workaround that would force the player to respawn after death on a green spot, while still only interacting with the bed from the light blue spot. The best workaround I have right now is requiring the player to interact again with the bed after sleeping (from a green spot), but this is easy to omit/forget and therefore not foolproof.