@Hung Pham.

You enabled Show single variation option under Theme Settings > Shop > Variable products, so you will see variable that has higher price but inside product, you will see smaller one only

Regarding the above. That was exactly my point when I first posted the problem. I want to see the variables as separate products. The problem is not that if this is enabled I see the higher price outside and the smaller inside. The problem is that if the catalog mode is enabled, because of the query that is created based on the attributes, it does not return the correct info.

Why do I insist this might be a bug based on the implication made by the theme?
Try to disable the catalog mode. After that, try to click the product with the higher price again and you will be redirected to the single product with the correct price displayed. Not the smaller or the lower.

What might be the problem here?

Disabling the cart/buy functionality from the woocommerce hook, there might be an error based on the implementation that creates the query, so the product price is not displayed correctly.

Let me know your thoughts.

Best Regards