Glow squid spawn naturally in various caves in my realm, and often quite frequently, up to around y63. They do not seem affected by y level or light level. However, they do not spawn in farms I have made. These farms have been variously below y40, y20 and y0. I have tried with magma bubble columns, no joy. With just stone blocks below and above, no spawn. With no light, using sapphire glass, nada. I have ensured there are no large pools of water within a 44 block radius. It’s a 4 chunk render on a standard Xbox realm. Yet in the same cave, about 75 blocks away, the glow squid will spawn in naturally occurring pools of water. Is this a biome-centric thing, or like a slime spawn chunk thing?? I can’t work it out.