Does the prayer of one who drops the hamza in "an'amta" and adds a waw after "na'budu" in Al-Fatiha become invalid, and must one repeat the prayer behind him?

First, the Imam should be advised not to absent himself from prayer. If he is compelled to do so, he should appoint someone who can lead the people in prayer properly. The young man must be taught the mistakes he makes that invalidate the prayer, because reciting Al-Fatiha is a pillar, and the prayer becomes invalid by omitting a letter from it, adding one, or substituting one, if he is capable of performing it correctly. It is not permissible to follow him in prayer. His prayer and the prayers of those who followed him are invalid and must be repeated, unless he is unable to do otherwise, such as being someone who, when taught, does not learn. In such a case, his prayer is valid for himself and for those who are like him.