Kangana Ranaut seemed to be in awe of Vijayendra Prasad and his team so much that, she gave him more respect than anyone else and Krish did not even care about the film, even though he directed at least 70% of it.
Actually, Krish completed the movie as he promised and producers asked for few re-shoots. He agreed to complete them and join NTR or do it simultaneously but then Vijayendra Prasad suggested some extra scenes, it seems.
Kangana Ranaut wanted them and Krish did not agree. Vijayendra Prasad encouraged her to shoot them in his absence as he thought the movie will definitely benefit from them.
Well, also with the changes in casting and few others hurt Krish so much that he did not want to talk about the movie, it seems.