When I Fighted against cave spiders, i defeated them all. but the spawner showed, that I am not finished, and there are some left. Luckily i had hitboxes turned on. so i saw the blue line of the cave spiders (the looking rirection) behind a wall. the cave spiders spawned inside of a mineshaft (blue arrow), that generated right next to the trail chamber. almost all cave spiders spawned outside of the trail chamber.

They supposed to spawn right next to the spawner (as yellow maked in the picture) inside of the Trail chamber.

Reproduce:
look at the screenshot. it contains seed and Coordinates.

Seed: -8848556164613702986
Coordinates: -1025 -25 794

Make sure to create the world in 24w13a i just updated it today to the newest snapshot.