Water Passive mobs like fish,squid spawning in air at y level 30~

Steps to Reproduce:
1. Drain the water at y level 30~ in ocean.
2. Wait for 10 minutes.
3. You will see fish spawning in this area.

Observed Results:
I am working on Ocean Monument Draining project so after the water was removed fish are spawning in the air where earlier water existed.

Expected Results:
Passive mobs/Fish should not spawn in air.

This was posted MCPE-88756 here too but closed as reporter did not respond.