Mu Wanqing indeed had known early on that her neighbor across the door had installed a camera outside, but she didn't mention it to the police or Ye Huan.
The reason she didn't tell the police was fairly obvious.
She didn't tell Ye Huan because she didn't want her best friend to think she was scheming to "trap" Chen Haoyang.
Her friendship with Ye Huan was genuine, but human nature is hard to predict, and she still needed to keep some reservations, not being too open-hearted.
If it weren't for Wen Zhan repeatedly lecturing and chastising her time and again, she wouldn't have told him about it.
The room quieted down, Wang Zhan slowly settled and felt that arguing back and forth was meaningless.
With her personality and temperament, even if she knew she was wrong, she wouldn't admit it at this moment.