Is "Bad manners spoil deeds" a Hadith? What is its درجه (degree/grading)? How do bad manners spoil deeds? And what is the difference between deeds being spoiled and deeds being annulled (frustrated)?

In summary: The hadith: "Bad character corrupts deeds just as vinegar corrupts honey" is not authentically attributed to the Prophet, peace and blessings be upon him. The corruption of deeds in this context means their nullification and the loss of their benefit. Bad character does not nullify all deeds unless it is associated with disbelief. However, it can affect good deeds by nullifying their reward, such as charity accompanied by reminders of generosity and harm, or fasting accompanied by ignorance and false speech. Moreover, bad character in dealing with people, like backbiting and slander, can lead to the transference of the wrongdoer's good deeds to repay injustices on the Day of Judgment, which diminishes the reward of their righteous deeds and may even lead them to Hell if their good deeds are exhausted.