fix

src/App.vue

@@ -50,6 +50,7 @@ function setupBackButton() {
     tgApp.BackButton.offClick(backHandler);
     backHandler = null;
   }
+  console.log('history legth:' + window.history.length)
 
   if (window.history.length > 1) {
     tgApp.BackButton.show();