Need help finding a certain book

I remember reading a fascinating Spirou and Fantasio story over twenty years ago in my library. They went into a parallel world were robots were building a white city, and attacking every living creature. They find out that the order was started by a human, who died in the control room, so the order was never revoked.

Does somebody know which book it was? Was it even S&F?

Please help 🙏🏻