May relate to MC-17298, MC-79366 or MC-93327

The bug

The advancement for killing a mob within the range of a sculk catalyst, entitled "It spreads", does not require that sculk actually spread as a result of this killing. As such, the advancement's name is somewhat misleading.

How to reproduce

1. Place a sculk catalyst in a region surrounded for a reasonable distance in blocks neither sculk nor sculk veins can spread to, such as mud (MC-249208)
2. Kill a mob in range of the sculk catalyst and on the mud blocks or whatever else was used
3. Obtain the "It spreads" advancement without spreading anything

Expected results

Either the advancement would require sculk to spread before being granted, or it would be titled something different to make it less misleading.