Only if the Imam has an innovation that nullifies Islam that we are not allowed to pray behind him. Otherwise, we should pray behind him if there isn’t any other suitable masjid. Ibn Omer may Allah be pleased with him used to pray behind Al Hajjaj and he was the one who demolished the Ka’abah and killed a number of the companions of the Prophet salla Allahu alaihi wa sallam and the Ta’abeen.

Is there any hadeeth which says that if a particular masjid or imam follows biddah or there is a problem with his beliefs one should not pray behind them?