Peace be upon you and God's mercy and blessings.
Grand Ayatollah Sayyid Sistani (may God protect him):
One of the conditions for a congregational leader (Imam) is that he must read correctly. It is not permissible to follow someone who does not read correctly, even if he has an excuse for his actions. It is also not permissible to follow someone who does not read correctly in the same place, and it is strongly recommended to avoid him even if they are in the same place. However, it is acceptable to follow someone who does not read correctly in a different place that the Imam is not responsible for, such as following him in the second unit after he has bowed or in the last two units. It is also permissible to follow someone who does not correctly recite the phrases for bowing, prostration, testimony, and the four praises if he has an excuse for not correcting them.
Grand Ayatollah Sayyid Khamenei (may God protect him):
If the Imam's recitation is incorrect in the opinion of the follower, and thus he believes the prayer is invalid, he cannot follow him. If he does follow him, his prayer is invalidated and must be repeated.
May you be successful in all good.