/spawnpoint not working in nether if block is specified

I was messing around with the new respawn anchors in the nether, and I wanted to try out the /spawnpoint command in the nether. Unfortunately, any time I used the command I would be told I had no home bed, respawn anchor, or it had been obstructed. This happened even if I died in the nether immediately after setting the spawn point.

 

Update: I was able to set my spawn point in the nether by using the command only if I did not specify which block to set my spawn to.