At intersections between Trial Chambers and Mineshafts, the Cave Spider spawners have a chance to generate inside the Trial Chambers.

To Reproduce

1.) Create a world with seed -4671324345858836738 and the update_1_21 datapack.

2.) Run the following command:

/tp @s 190 -44 55

3.) Look at the ceiling. A Cave Spider monster spawner from a Mineshaft has generated inside the Trial Chambers.

Expected Result

The Cave Spider spawner is overwritten by the Trial Chambers generation along with the rest of the Mineshaft.

Observed Result

The Cave Spider spawner is not overwritten by the Trial Chambers, although the rest of the Mineshaft is.