Although the status shows field but it can solve for the correct value and there is a slight drop in the output value when convergence is near, what are the reasons for these problems and how can they be solved?

As with @Erling , I’m not sure what you are talking about.

But I will make a guess that you are calling CVX in an iterative manner, such as SCA, and do not find the overall SCA algorithm to be performing as you would like. For instance, the optimal objective value (per SCA iteration) is not monotonically increasing (i.e., improving, given that you are performing maximization) . If so, see