I have set a list of items into the session using this piece of code

session.setAttribute("selectedList",listSelected);

Later, I wanted to remove that selectedList attribute from the session on clicked event of a button, like so

<button type="reset" style="text-align: center" onclick="function openPage(pageUrl) {
                        sessionStorage.removeItem('selectedList');
                        window.localStorage.removeItem('selectedList');
                        window.location.href = pageUrl;
                    }
                    openPage('/TN2_war_exploded/SupplierPage/SupplierSearch.jsp')">Cancel
        </button>

Despite trying both methods, sessionStorage.removeItem and window.localStorage.removeItem, when I move back to the page, the session still holds my list and informations within are still displayed

What did I do wrong? any tip is appreciated