Sunan Abi Dawud Book 2, Hadith 435
Makhul used to recite Surah al Fatihah al-kitab quietly in the prayer in which the imam recites the Qur’an loudly when he observes the period of silence. If he does not observe the period of silence, recite it before him(i.e before his recitation), or along with him or after him; do not give it up in any case.
“Ubadah b. al-samit came to late to lead the morning prayer. Abu Nu’aim, the mu’adhdhin, pronounced the takbir and he led the people in prayer. Then Ubadah came and I was with him. We Joined the row behind Abu Nu’aim, while Abu Nu’aim was reciting the Qur’an loudly. Then ‘Ubadah began to recite the Umm al-Quran (I.e Surah al Fatihah). When he finished, I said to Ubadah: I heard you reciting the Umm al-Qur’an while Abu Nu’aim was reciting Qur’an loudly. He replied: yes> The Messenger of Allah (ﷺ) led us in a certain prayer in which the Qur’an is recited loudly, but he became confused in the recitation. When he finished he turned his face to us and said: Do you recite when I recite the Qur’an loudly? Some of us said: we do so; this is why I said to myself: What is that which confused me (in the recitation of ) the Qur’an. Do not recite anything from the Qur’an when I recite it loudly except the Umm al-Qur’an.
When the Messenger of Allah (ﷺ) finished a prayer in which he had recited (the Qur'an) loudly, he asked: Did any of you recite along with me just now? A man replied: Yes, Messenger of Allah. He said: I am wondering what is the matter with me that I have been contended with reciting the Qur'an. He said: When the people heard that from the Messenger of Allah (ﷺ) they ceased reciting (the Qur'an) along with him at the prayers in which he recited aloud.
Abu Dawud said: This tradition reported by Ibn Ukaimah has also been narrated by Ma'mar, Yunus, and Usamah b. Zaid on the authority of al-Zuhri similar to the tradition of Malik.