What is the reason for the continued assault of jinn in dreams (amorous possession) upon a Muslim, despite their commitment to prayer and morning, evening, and pre-sleep remembrances?

The fundamental principle is that adherence to obligatory prayers and remembrances (adhkar) protects a person from the dominion of jinn. However, one may be afflicted by jinn possession during times of heedlessness, or if the possession occurred before one began to regularly observe the remembrances. In such cases, one needs ruqyah shar'iyyah (Islamic exorcism) performed by someone who adheres to the Sunnah. It is essential to maintain regular remembrance with contemplation and presence of heart, and to sleep in a state of ritual purity (tahara). One should also humble oneself before Allah Almighty and ask Him to remove the affliction. Sheikh Al-Jibreen mentioned that some jinn appear to humans, male or female, in human form and engage in intercourse with them. The remedy for this is to protect oneself from them with the prescribed supplications (du'as), وردs (regularly recited invocations), and verses that include protection and guardianship.