What is the ruling on praying behind an Imam who recites the Qur'an with a congregation in unison and with one voice every Friday after Fajr and Asr prayers, and similarly in Ramadan after every Fajr and Asr prayer?

Recitation in the manner mentioned is disputed in its permissibility, and its practitioner should be gently advised to abandon it. Prayer behind him is permissible and valid without difficulty, because the issue is one of dispute, and the preponderant opinion is the validity of prayer behind every Muslim.