Stone-based redstone ore generating in deepslate

Put the summary of the bug you're having here

What I expected to happen was...:
Redstone deepslate ore would generate in deepslate at layer y = -9

What actually happened was...:
Redstone ore was generated

Steps to Reproduce:
1. start a world with seed 4459428897809537864 with lush caves single biome mode enabled
2. go to coordinates 475.36 -9.00 333.67