I found an odd issue a while back in roughly 1.16.5 on my old 2010 Mac-book where I was moving my cats in boats with water, but on a couple of occasions they flowed into the block below them and suffocated to death; I tried recreating it again on my new Dell G15 5510 gaming laptop on 1.18.1, with success, and as I have recording software on this laptop, I was able to capture it happening.

It was a bit hard to recreate, however (trying to recreate it was like when you accidentally make a fart sound with your shoe against a loose rock on the ground while walking with friends, and they accuse you of letting one rip, but it was just your shoe, however, you can't make your shoe do the fart sound again, so you have to live with them accusing you over a fart that you didn't do).

In the first video I have, the issue happened while I wasn't looking directly at the boat, but I turned to find where the noise was coming from, clearly hearing the cats dying, then their death sound, death particles, and their drops of string emerge from the ground. In the second video I have, I managed to capture another boat do this issue while it was within my field of view, and the same things happened: cats suffocating, they die, then their drops + death particles rise from the ground. I dug to find the boat I captured on video, and once I found it, I walked over to the place where the first boat went under and found that one too. I have only seen this happen with cats in boats, I haven't seen or tried this with other mobs as of yet.

I tried to attach the videos I mentioned to this issue document, but they exceed the file size limit posed by this website a bit over sixfold. However, their links below have managed to stay in text form. I double-clicked on them and opened them both in new tabs, and they showed me the videos I tried to attach; I don't know if the text links will stay that way when I submit this issue, but I will submit it anyway and hope for the best.

[^Minecraft 2021.12.28 - 02.03.36.04_Trim.mp4] [^Minecraft 2021.12.28 - 03.45.03.08_Trim (2).mp4]

[^Minecraft 2021.12.28 - 02.03.36.04_Trim.mp4]