Summary:
Whenever you set the spawn in a respawn anchor and die right afterwards (if you set it as you're falling, for example) the respawn anchor is marked as obstructed/without charges(even though it's not either of them) and you spawn at the world spawn. If you do the same with a bed, you'll spawn right next to the bed as intended.

Steps to Reproduce:

1. Place a respawn anchor in the Nether
2. Charge it with glowstone
3. Fly high enough above the respawn anchor so that you'll die when falling
4. Switch to Survival mode
5. Right as you are about to hit the ground, set your spawn point to the respawn anchor
6. Press the respawn button

Observed Results:
The player respawns at the world spawn with the message "Your respawn anchor was out of charges, missing or obstructed"

Expected Results:
The player respawns near the respawn anchor.