I've been having fun building in the 1.17 snapshot 21w08b and I'm making an underwater cave house. I'm trying to add glow squids because they look nice and they seem to (they don't actually) produce light so I don't need to use sea lanterns, glowstone, glow lichen, etc. to light up the water. I used a spawn egg and placed a lot but they all disappeared whilst I was doing some terraforming away from them. I thought it was normal, I went a bit far away, though I was confused why a passive mob would despawn, even if I wasn't too far away. Next, just to be safe, I named the glow squid egg (I just named it "."). After spawning, they stayed a bit but despawned again. At this point, I knew something was not right. I tried again, but knowing they would just despawn, I added glow squid spawners. I waited for a while, just watching them to see if they would despawn or just die for weird some reason. As I watched, I saw them just disappear one at a time, some did right in front of me. The spawners also didn't spawn anything. If it helps, It's at around Y:3 and the cave is in a plains biome. There are some places for them to swim away, but I'm pretty sure they aren't just swimming away because I saw them disappear in front of me multiple times and nothing is coming from the spawners. Hope someone can help or at least say why this is happening. I don't even need a solution, (though that would be great if I could get one!) I'm just curious of why its happening.
UPDATE: i tested the spawners again and they do actually spawn some, its just very slow and only when im right next to it, so, i't doesnt seem like a viable solution