Al-Ibanah an Usul al-Din is a distorted book. Why?

Praise be to Allah, The Lord of the universe and May Allah, the All Mighty, raise the rank of the best of all His Messengers, Prophet Muhammad, and raise the rank of the blessed and virtuous kins and companions of our dear Messenger. God has destined, for this Umma, those who will protect Islam, defend its beliefs, and refute its opponents with the proofs of the Noble Qur'an, the Sunnah of the trustworthy Prophet, may Allah raise his rank, and the evidence of sound intellect. Sheikh Abu al-Hasan al-Ash'ari was among those who supported the religion accepted by God by teaching, debating, and authoring. God tested him with those who bore him enmity during his life and after his death, as they fabricated false and baseless claims against him and his followers, including the claim that "he reverted from the belief of the People of the Sunnah, which is based on God's absolute uniqueness, to the belief of the Anthropomorphist's, which is based on anthropomorphism "And those who slander this noble doctrine claim that, after deviating towards the doctrine of anthropomorphism (tajsim), he authored a book titled 'Al-Ibana an Usul al-Diyana' which means ‘The Clarification of the Principles of Religion). However, their claim is baseless and falls apart from several angles. The students of Sheikh Abu al-Hasan refute them, and history exposes their falsehood. The rest of the Sheikh's works clearly demonstrate that he remained steadfast on the truth until his death, and their contents align with what his students narrated and what millions of Ash'aris have adhered to from his time until ours.