What's the issue you encountered?

In a body of water (at or near sea level) within a BoP biome, squid will spawn at high rates. This behavior was removed in vanilla as of 1.13.1, so it may be a remnant of that?

How can the issue be reproduced?

Find or make a lake in a BoP biome, near sea level. Wait near it for a bit. It will eventually be full of squid.

Mod Version

1.14.4-9.0.0.252

Has nothing to do with BOP. We don't touch squid spawn rates, and that can happen in any vanilla biome.

This doesn't happen in vanilla though. Like I said, this behavior was removed in vanilla biomes in 1.13.1, so this only affects BoP biomes.

You should've been more clear. I wasn't aware that they were removed from normal biomes, and thought you just meant the spawn rate was too high, when they shouldn't have been spawning at all.