Bai Liyue didn't put many unmanned cameras in the Imperial City before entering, so she didn't know how big the Imperial City was, how many gates there were, and what was in each gate.
She had only probed the situation at the city gate she was at.
The more things she got, the more interested Bai Liyue became. Unknowingly, she had already come to another area.
The disciples of the sects in this area all entered from another city gate.
That city gate was a side gate, and there were few zombies guarding it. Although everyone used their full strength, the number of casualties was very small.
Therefore, when Bai Liyue and the others arrived in this area, they found that there were obviously more people in this area. Furthermore, he had never heard anything about Baili Yue and Yingying.