/locate command don't work on superflat

I was trying to locate a mansion in a supeflat world to try to transform it. I made sure that the biomes is set to dark_forest and other requirements for it to spawn. After that, I tried to use the "/locate" command in order to find what i'm looking for. Suddenly, the command feedback said "Could not find that structure nearby". I was so confused and start checking what i did wrong and there is nothing i found.

Until I started a new superflat world and found out that what i use the "/locate Village" command to test it on a village. Then, the command feedback said "Could not find that structure nearby" even if the village was just right behind me. I was like "How is this happening???" I was searching on YouTube on how to fix this, then YouTube did not understand my query meaning no one has ever noticed this yet. So I decided to report it.