Does the prayer become void if the Imam, while reciting Al-Fatihah, connects "Ar-Rahman Ar-Rahim" with "Maliki Yawm Ad-Deen" without vocalizing the kasra of the letter Meem in "Ar-Rahim"?

The prayer of one who recites "Ar-Rahmanir-Rahim Maalik" and connects "Ar-Rahim" with "Maalik" through idgham is valid, provided the meaning does not change. This is because it is a major idgham, which is the reading of As-Susi from Abu 'Amr. However, As-Susi reads "Malik" and not "Maalik." So, if the imam reads it as "Maalik," he has combined different readings. This is permissible according to some scholars, as long as it does not result in a linguistic construction not allowed by Arabic grammar or a fabrication in the narration.