What is the ruling on the prayer of congregants behind an imam whom they dislike, and is their prayer valid despite frequent distraction, or is it not permissible to pray behind him? And what should be done in this situation?

If the congregants dislike the imam due to a defect in his religiosity, it is permissible to report the matter to the authorities. The imam should not lead the people in prayer if they dislike him, especially if the majority or the best among the congregation dislike him. However, if the dislike is unfounded and the imam is religious and adheres to the Sunnah, then the dislike falls upon the congregants.