Hi Tin, Welcome to the community!
Your result looks correct to me. When you use the best solution, the result will be one solution that is shown in the .pos file. Meanwhile, when you choose all solutions, it will show all possible solutions in the .pos file.
I suggest using the best solution option, ES will give the best estimate of the position by an EKF (extended Kalman filter).
Additionally, we do have a discussion about this “one best” in this thread: Does the "one best" option average all fixed ponts? - #13 by daygeckoart