I was traveling, so I prayed the 'Asr prayer with two rak'ahs behind a resident imam. I was told that my prayer was invalid. What is the ruling on my prayer?

Question:
May Allah reward you, Honorable Shaykh. This questioner says: I was traveling and entered the mosque during the 'Asr prayer. I had missed two rak'ahs, so I prayed two rak'ahs with the imam and then said the taslim with him. A man standing next to me told me that my prayer was invalid and that I must repeat the prayer, because when you pray behind a resident, you are required to complete the prayer. The question is: Is his statement correct? Is my prayer invalid? And what is obligatory for me?

Answer:
His statement is correct, and your prayer is invalid. Because when you pray behind someone who completes the prayer, you are required to complete it, and it is not permissible for you to shorten the prayer behind someone who completes it. So repeat the prayer. May Allah bless you. Yes.