It’s possible that someone has built right above the cave, which will prevent the crocodille boss from spawning, could you please confirm if this was the case?
Technically preventing you from playing the game in its fullest form from beginning to end. Just saying, this area should just be no build zone already.
There is a door in that cave. Perhaps the door will lead to a future dungeon and the croc can also be moved into the dungeon so that its spawn is safe.