At what point did the Kurama stop sucking Naruto's chakra?
I think it was somewhere between the conversation when Naruto said that he will take all Kurama's hatred and when Kurama heard him say that he doesn't regret being Jinchuuriki when he fought Tobi and other Jinchuurikis in the forest. Because till then at one point Naruto runs out of the Kuramas chakra so at that time he was still taking it from him. So definitely after real Madara showed up. I think.