The ruling on one who missed a rak'ah of the 'Isha' prayer, said the taslim with the imam, and then repeated the prayer

Question:
Abu Muhammad is with us on the line, please go ahead, Abu Muhammad. Peace be upon you, and Allah's mercy and blessings. And upon you be peace. The first question, Abu Muhammad. Regarding the adhan for the 'Isha' prayer, I entered the mosque and I missed the first rak'ah, and I prayed with them and the imam said the taslim and I said the taslim with them. I forgot, I said the taslim with them. Then I repeated the prayer alone. Yes, that is something. Okay, he says: He entered with them into the 'Isha' prayer and he missed the first rak'ah, but he, Shaykh, said the taslim with the imam and then repeated the prayer afterwards?

Answer:
He said the taslim before completing the prayer. Yes, Shaykh. It was obligatory for him to stand up and perform the missed rak'ah and prostrate for forgetfulness, but since he repeated the whole thing, we ask Allah to accept this. Yes.

The presenter:
May Allah reward you.