Minecraft mushroom island no caves?

I wanted to ask an expert here how it is with caves on mushroom islands… I happened to spawn on a mushroom island in my hardcore world (1.16). There's also a mesabioma - the perfect spawn. I've been playing in the world yesterday and haven't found a cave yet. So on the mushroom island where I need one. I know that mobs can't spawn on mushroom islands, but what about caves?

Here is the seed: -5723029003027562915

Yes, caves can spawn on mushroom islands like everywhere.

Ok thanks then I must have been a bit unfortunate