If a regenerating axolotl is caught in a bucket and released, the regeneration effect will disappear and the axolotl will become very weak.

Also, this does not correspond to the bedrock version, where the axolotl, after being released from the bucket, continues to regenerate.

Notes:

In the bedrock version, there is a bug in which the axolotl starts to swim after being freed from the bucket MCPE-130041 (after fixing the bug with regeneration, this should also be taken into account).

Video:

Bedrock Minecraft 2021-06-13 20-32-25.mp4

Java Minecraft 1.17 - 2021-06-13 20-29-37.mp4