Axolotls despawning

Seem to be encountering a problem with axolotls despawning, which is especially annoying since they seem to spawn so much more infrequently in the new update. I had three axolotls: one cyan, one leucistic, and one gold, and I had them in buckets and released them into an aquarium so I could breed them. I know in previous versions that mobs could despawn in Bedrock if they’re on a chunk border while the chunk loads so I specifically built the aquarium within the boundaries of a chunk. But after releasing them I was afk for about ten minutes, in the same chunk, and came back to find the gold one disappeared with no death message. Since catching them is rarer now, I put the other two back in buckets and am gonna avoid releasing them until the issue is confirmed.