Why is Mickey Xuan Shi called Tianjin Master?

Because glyphs sound similar.

In China, Mijin Xuanshi is often misunderstood as a master of Tianjin, and at the same time, it is also misunderstood as lawyer Mixuan, lawyer Mickey, Mijin Xuan Shi, and Milu Xuan Shi.

Even the Japanese often mispronounce his name. Before they knew it, many people always thought it was the legal name of a monk who watched Feng Shui or exorcised demons.