Yes, when Dev didn't listen to Sona and went directly to Ish and argued. It was totally wrong. I agree. But he was worried for Sona. He thought she is been forced to follow the things she don't believe in. She never did fasting before and he's aware of all that.
And about DevAkshi's fight, for me both of them were correct with their respective POVs... Dev is angry as he thinks Sona is losing her identity by getting into pleasing the family and doing something she don't believe in. He was thinking why is she trying to be someone else. And Sona on the other hand just want to get along with the whole family. Want to learn their customs. So that they'll wholeheartedly accept her as the daughter-in-law of the house. She's making her efforts, which is good.
Dev is not aware that his mother has not accepted Sona yet. As she always pretends infront of him and he believe her way too much. Yesterday when Dev confronted Ishwari and she was talking about trust, the thing that came in my mind is, what will happen when Dev will come to know about the prenup. What will she say then?
And for resolving the argument. They fought just when he was leaving for the work. So there's no point in thinking he would have immediately come to talk about it considering their frame of minds at that point of time.
But definitely they'll resolve the issue today itself. Both of them know each other very well. They cannot stay angry for a long time.