My creeper farm has also stopped blocking spider spawns, this is the configuration of the buttons. Torches are temporary so you can see the buttons. Usually it is pitch black in here. 🙂
The changelog says they changed how the position was chosen and mentioned that cardinal directions were prioritized over corners, but they didn't say they've remove the majority of spawnable locations entirely. So I think this is actually a bug and not a Works As Intended.
this also exists on bedrock