I heard Sai Baba promised to attend Dev's Udyapan ceremony but then broke his word. Can you clarify what happened?

This is a common misunderstanding that Dev himself initially shared. According to Chapter 40, Dev felt disappointed and wrote to Jog that he believed Baba had deceived him. However, Baba later clarified the entire incident to Jog. He explained that he had indeed attended the ceremony, but in the guise of a Sanyasi. He first appeared alone and then returned for the meal with two companions, exactly as he had foretold. Baba emphatically stated, "I said I would come with two others, and I went with two others... for the sake of My word, I would die; but the words from My mouth shall never be otherwise." Dev's inability to recognize him in this form led to the initial confusion and feeling of being let down.