Ive been running a raid farm on my survival world that uses a piston trident killchamber, the entire raid has a very small chance to spawn inside of the 2x2 killchamber i have setup, it usually happens in the earlier waves of the raid when only one ravager is present. The killchamber is less than 4 blocks from the player, this wouldn't be an issue if the mobs were prevented from spawning within 10 blocks of the player.

https://drive.google.com/file/d/1GaheGPAd9Yj-0XAtMMHrJfBhpnjTpvI_/view?usp=sharing

Once the world is opened, the player should be positioned at the raid farm where the issue is present, do not reposition the player and run for about an hour, the issue should happen within that period.