Why can some squares be circled repeatedly when Karnaugh map is simplified?

Why can some squares be circled repeatedly when Karnaugh map is simplified?

Both sides are logically adjacent, for example, ABC three people, a and B are adjacent, B and C are also adjacent, a circle can only circle 1,2,4,8 minimum or maximum items. You just need to ensure that at least one minimum or maximum item in each circle has not been circled by other circles