Is one who graduates from a Sharia college and works in a field other than their specialization sinful, knowing that they previously worked in dawah (preaching), imamate (leading prayer), and khateebah (delivering sermons), then traveled abroad for work due to financial circumstances, which distanced them from memorizing the Quran and studying knowledge, and they did not have a stable job previously available in their field?

There is no sin upon you for your current work in Da'wah as long as you fulfill your agreed-upon duties. There is no sin upon you for the new job if it is free from শরী'আ-prohibitions, even if it distances you from studying the obligatory knowledge. We advise you to remain in the new permissible job until you arrange matters of marriage and housing. Try to combine work with completing the memorization of the Qur'an and seeking Shar'i knowledge.