What is the ruling on praying behind someone who recites "مالك يوم الدين" (Maliki Yawm al-Din) with a fatḥa over the lām and the kāf?

Reciting "Maliki Yawm al-Din" (Master of the Day of Judgment) with an open lam and kaf (Malak Yawm al-Din) is a melodic error (lahn) that alters the meaning in Al-Fatiha, invalidating the original meaning or changing it to another meaning. If the Imam makes melodic errors in Al-Fatiha despite being able to learn, his prayer is invalid. However, if he is unable to learn or time is short, his prayer is valid for himself and for those who follow him and are similarly incapable. As for those who are not incapable of reciting Al-Fatiha correctly, their prayer is invalid if they follow him while aware of his condition. Their prayer is considered valid by some scholars if they were unaware.