second try

js/src/scrollspy.js

@@ -127,7 +127,6 @@ class ScrollSpy extends BaseComponent {
         event.preventDefault()
         const root = this._rootElement || window
         const height = observableSection.offsetTop - this._element.offsetTop
-        window.history.pushState(null, null, event.target.hash)
         if (root.scrollTo) {
           root.scrollTo({ top: height, behavior: 'smooth' })
           return
@@ -222,6 +221,8 @@ class ScrollSpy extends BaseComponent {
 
     this._clearActiveClass(this._config.target)
     this._activeTarget = target
+
+    window.history.pushState(null, null, target.hash)
     target.classList.add(CLASS_NAME_ACTIVE)
     this._activateParents(target)