Icons like duplicate an element are displayed but not executed
I think we need more information. There is no button or icon for duplicate.
When you Alt or Opt drag to duplicate, you will see a black and white arrow cursor, indicating that when you move your mouse you will duplicate the object. Is that what you are referring to? If so, start by rebooting your computer and try again. Sometimes other applications will interfere with the InDesign modifier keys.
Thanks for reaching out. I agree with earlier responses. In addition to provide answers to the questions asked earlier, would you mind sharing the version of the OS? Also, please share a screenshot of the icons you are talking about.
I'd also request checking out this help article to know how to manage your workspace. Hope it helps.