I feel like this is kind of prank, is this what you are telling me after spending 2 weeks time? Did you even read the previous messages. Here you go, copying the same screen shot https://imgur.com/yxvxgEM and copying the same description that you skipped to read
add a product to a cart, and then instead of going to "checkout" step, go to main page or any other page, the cart symbol with added product gets DISAPPEARED on the page which is normally on the right top position of the site always, the icon gets lost completely and it does not ocme back unless you add another product to the cart. It should take 1 min to see the issue on your end. Let me know if it is clear now
I tried by 4 different computers and different browsers, the issue persists. Keep in mind that Chrome is showing the cart and other browsers do not, try with different browsers. I tried with windows computer, the icon was not visible, I tried with Safari, icon was not visible again. Only chrome showed it most of times