Minecraft: Why do Creepers spawn in exactly the same place over and over again?

In my house I'm currently building spawnen always on the same block Creeper. Respectively. Spawns out of the air. It sounds like a command, but the problem came out of nowhere. There are no tutorials on the problem either. I thought maybe someone here knows a solution.

Strange, but if the environment is not lit, and not exactly with the radius, etc., it may well be that mobs spawn there. But certainly not just Creeper.

Do you have dark areas somewhere? Or start MC again or set the difficulty to peaceful and back to light, normal or difficult

Then exactly the place is not lit.