What was the specific problem Das Ganu faced with the Ishavasya Upanishad, and why did he seek out Sai Baba?

According to Chapter 20, Das Ganu was working on a commentary called "Ishavasya-Bhavartha-Bodhini" to explain the Upanishad's meaning in simple Prakrit language for those who didn't know Sanskrit. Although he had completed a word-for-word translation, he felt a profound dissatisfaction. The text states his mind "found no joy" because he had failed to grasp the "internal secret" or the deep, underlying meaning of the scripture. This intellectual and spiritual roadblock is what prompted him to travel to Shirdi to take his doubt to the feet of his Satguru, Sai Baba, for resolution.