I'd move the fish to some fresh dechlor'd water and drain the tank and clean it... what kind of shampoo specifically?
Not interacting with you is also not good. Even when he is not hungry, he should react to you. What exactly are all your main water parameters (temperature,
Still a mystery though with the bloat. Is it where normally his belly sticks out after eating just bigger, or a different place? After my puffers eat
Its been setup for a year and its cycled though the standard juwel lido filter.