Why did Ji Yunhe turn against Changyi?

There may be the following reasons why Ji Yunhe turned against Changyi:

In order to get rid of Changyi, Ji Yunhe not only stabbed him, but also pushed him off the cliff.

(2) Ji Yunhe didn't mean to hurt Changyi. She was poisoned by frost and knew that she didn't have much time. She didn't want Changyi to give up her freedom for herself and become a plaything in Shunde Ji Xian.

(3) Ji Yunhe deliberately slandered Changyi, and finally pushed Changyi off the cliff, hoping Changyi could leave himself.