Why did the Great Messenger (peace be upon him) not oppose the Jews regarding the issue of delaying a man from his wife, as he did when he married Fatimah (may Allah be pleased with her), where he delayed his entry to her, following their example?

The hadith is not established through any of its chains. Al-Dhahabi deemed it weak, and its chain includes Umar ibn Salih, who is very weak. The chain narrated by Al-Nasa'i includes Suhayl ibn Khallad, who is unknown. Furthermore, contradicting the Jews was not legislated at the beginning of the Prophet's migration (Hijra), but rather afterwards. In the early days of the Hijra, Muslims did not distinguish themselves from the People of the Book. When the religion was perfected, became manifest, and prevailed, then contradiction was legislated. It is reported in the two Sahih collections (Bukhari and Muslim) that the Prophet, peace and blessings be upon him, loved to agree with the People of the Book in matters about which he had not been commanded.