I believe you have a point there. Since Mane left Liverpool and joined Bayern Munich, I haven't even seen any of his impressive performances. Occasionally, you hear that he is injured and won't be able to play well. From what I understand, moving some players from one team to another without giving them the opportunity to get well-trained with their new teammates can have a negative impact on their careers.
Anyone knows how low Sadio Mane performance was when he was at Bayern Munich, this was of course driven by several important factors, especially the incompatibility of Mane and the Bayern Munich players, then the coach who at that time also did not give full trust to Mane even though he put him as a striker though. So when compared to Mane at Liverpool it was his golden age and Klopp fully believes that Mane's skills are very useful in sharpening the front lines. But at Bayern Munich, of course, the treatment was not like that, Bayern Munich put more emphasis on all of their players being able to play individually, while Liverpool made Mane and Moh Salah the main centers of attack.