Does Ganlong really know a princess?

In 1 and episode 35, Gan Long didn't give Wei Zigulun or Heshuo the title, but gave Wei Zi the identity of Gege, indicating that Gan Long didn't recognize the girl, so Gan Long didn't recognize a Gege.

2. Princess Zhu Huan mainly tells the story that Xia Ziwei, a rich girl, came to Beijing from Jinan to find her biological father during the Qianlong period. After several twists and turns, Xia Ziwei and Xia Xiaoyan became sisters.