fmincon reach the minimum of object function

I am confused while using the fmincon to search the minimum of an object function. Question 1: using the fmincon and stop(controlled by the optimization function to make the max iteration a small value, say 20) and then I get the one output. Then I continue to search the minimum using this output as the input of the fmincon's first guess. What I find is that the fmincon will change the searching direction and step, and sometimes the object function value will first increase and then decrease. How could it happen?

Question2: base on first Question, Here is the screenshot of the output. The object function value will increase in the 30, how could I make the searching more efficient to get the minimum of object function?