Hello. You did not inform the story to which this question refers, which makes it impossible for it to be answered accurately. However I will try to help in the best possible way.
If the narrator changes over the course of the story, it means that the narrator's feeling about something or someone has changed during the story. The narrator may be showing his discontent with alpha, which changes his mood during the narration. The opposite can also happen and the narrator can change the feeling he has about something in a positive way.