What are the reasons for repeated difficulty in engagement despite having good morals, and what is the solution to this problem?

A delay in marriage does not necessarily mean it is due to magic (sihr), the evil eye (ayn), or jinn possession (mass). Rather, it could be due to ordinary reasons, and marriage is a provision decreed by Allah. What the brother saw in the dream might not have any relation to marriage or magic. One should increase supplication (dua') and ask Allah for facilitation, for He answers the distressed. If there is a strong suspicion of an unusual matter, then one should resort to ruqya shariyya (Islamic exorcism) and continue reciting the Quran in the home, especially Surat Al-Baqarah, for Satan flees from a house in which it is recited. Taking it is a blessing, and abandoning it is regret, and the sorcerers cannot overcome it.