respawn anchors with no blocks around it don't work

The Bug

respawn anchors with no blocks around it spawns you to your actual spawn point (in the overworld) despite using it and uses a charge! BIG scam

 

How to reproduce

1. delete the blocks around a respawn anchor in the nether
2. fill up and right click the respawn anchor to set spawn
3. die
4. observe the glitch occur