Setting world spawn in the nether and dying causes you to respawn at bedrock

Using the command /setworldspawn in the nether and dying in other dimensions will respawn you at bedrock even when there isn’t an available spawning location* and there are blocks above you. Using /gamerule spawnRadius 0 does not help this. Dying in the nether is especially strange because it seems to happen at random the more I look into it. I thought it was depending on the height I died at, but then it started happening at all heights, then I thought it was the block I was standing on but it started happening on blocks I thought were safe. The one place it happens without fail in the nether is when I’m flying in creative and /kill over a lava lake.

*What I mean by no available spawning location, I mean you spawn inside blocks at bedrock, not an available air pocket down by bedrock, but physically inside the bedrock block.