Sure seems like Fenix Flexin used AI music generator Treblo
The Verge
Treblo's new AI music classifier indicates that Fenix Flexin's song "Rubberz" was generated using their model.Summary
Musician Medasin and the AI company Treblo suggest that Fenix Flexin's song "Rubberz" was created using Treblo's AI music generator. Treblo recently released an open-source classifier with a very low false positive rate, which determined with high confidence that "Rubberz" was generated by their model. While Fenix has denied these allegations and shared purported project files, critics argue those might be faked using stem separators. If confirmed, "Rubberz" would be the first known AI-generated song to reach the Billboard Hot 100.
(Source：The Verge)