Is forgetting the memorization of the recitations after having known them included in forgetting the memorization of the Holy Qur’an, which is considered unlawful?

Scholars have differed regarding the ruling on forgetting the Qur'an: some say it is a major sin, others say it is a disobedience that does not reach the level of major sins, and still others say it is a calamity or a punishment. As for forgetting the recitations (Qira'at), it is not like forgetting the Qur'an, and its perpetrator is not sinful, but he misses out on a virtue. It is incumbent upon the student of recitations to preserve them and review them.