I'm managing a server with some friends and one of them came to me thinking their axolotls were stolen. After checking the console, it turns out they both died on farmland blocks due to not being in water/dehydration and it reminded me of how dolphins when out of ai range will still suffocate. I'm not sure if that is what happened but it seems logical since I recall their pathfinding being improved recently. However, my friend was devastated that the axolotls died. It may also relate due to farmland not being a full block but either way its sad.

I've attached a picture of the farmland in question. The hanging vines did reach all the way to it at the time.