Baby drowned no longer produce chicken jockeys from nearby chickens (26.3 regression)

Baby drowned no longer appear to remain as jockeys when they encounter nearby chickens. This breaks farms that rely on baby drowned mounting existing chickens.

The farm shown in the attached screenshot was working as recently as Halloween 2025. I cannot determine exactly when the behavior changed.

Reproduction / setup

The farm consists of a fully dark, 3-high spawning chamber with:

• 2 blocks of water at the bottom

• 1 block of air above the water

• A roof made of tinted glass

• Chickens positioned 2 blocks below the spawning floor on bottom trapdoors

• Top slabs above the chickens arranged in a checkerboard pattern

When a baby drowned spawns in the chamber, it should perform its nearby-chicken check and mount one of the chickens.

Expected behavior

Baby drowned that encounter a nearby chicken should remain mounted on that chicken as a chicken jockey.

Actual behavior

I am no longer getting drowned jockeys from the farm.

Occasionally, I find baby drowned in the chicken area holding eggs. This suggests that the drowned may successfully mount a chicken and subsequently dismount, since the chickens are the intended mounts and the drowned can then pick up an egg. However, I have not directly witnessed the mounting/dismounting event, so I cannot confirm that this is what is happening.

Additional observations

I have equivalent versions of this farm for baby zombies, husks, zombie villagers, and zombified piglins, and those continue to work. This makes the issue appear specific to drowned rather than to the general nearby-chicken jockey mechanic.

The drowned occasionally being found in the chicken area holding eggs is consistent with the possibility that they are reaching the chickens but failing to remain mounted.

Hypothesis

My current hypothesis is that the ordering of the drowned's chicken-mounting logic relative to its water-state/location update may have changed.

One possibility is that the drowned mounts the chicken before its position/state is updated, causing it to still be considered underwater when the game checks whether it can remain mounted. If so, this could cause the drowned to fail to remain mounted and subsequently pick up an egg.

I have not verified this behavior directly; this is only my best hypothesis based on the observed results.

Related issues

This seems potentially related to MC-211217 and MC-261125. However, those reports were created in 2021 and 2023, respectively, while this farm was still working as recently as Halloween 2025. If they are related, this would appear to be a regression/reintroduction of the behavior.

It also appears related to MC-209784, but there is an important distinction: this report concerns a drowned mounting an existing nearby chicken, rather than spawning already mounted on a chicken. Additionally, in this case the drowned's head is not underwater when it would be expected to remain mounted.

Version / environment

• Java Edition 26.3

• Reproduces in vanilla 26.3

• Also reproduced with Fabric mods installed

I am happy to provide additional information or testing if needed.