Cached pages doesn’t update on change until browser refresh

Hey all,
I have a strange problem at
I changed  some styles and plugins, but if a client re-visit a product he viewed in the past, he will see the old website, for example I added a mini floating cart from checkoutWC plugin, it doesn’t show in next visits until client force a refresh, same thing after disabling it, it still shows to client until refresh.
I think it is a cache problem, but I cannot know how to fix it, I purge all cache from server side, so I think it is a browser cache problem, how can I solve this ?

even the front page, if I change it or add product, it doesn’t update until client force refresh the page.

The page I need help with: [log in to see the link]


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