Drowned doesn't spawn inside aquifers in the dripstone caves

On Java, the drowned can spawn inside aquifers in the dripstone caves. However on Bedrock, they don't, which creates parity issues between both editions.

Step to Reproduce
1. Find a dripstone caves with aquifers.
2. Try to let monsters spawn inside, if not, clear the mob by using /kill @e.

Expected Results
Drowned can spawn inside aquifers in the dripstone caves.

Observed Results
No drowned spawn inside aquifers in the dripstone caves.