为什么我的管理员账户在前端没有更改主题的选项?

So normal users on your site can see the dropdown, but your account can not? is that accurate? I just want to clarify because I think your screenshot is from this site (The Meta Branded theme isn’t available elsewhere).

If normal users on your site can see it, I assume you have multiple themes installed with “Theme can be selected by users” checked?

Do you get different results in safe mode?