UI functionality correction

app/templates/elements/LeftVerticalNavBar/heartNavBar.html

@@ -1,6 +1,6 @@
 <div class="navbar-nav w-100" id="heart_left_nav_bar">
     <a href="#" class="nav-item nav-link dropdown dropdown-toggle" data-toggle="dropdown" id="dropdownmenu1" role="button" data-bs-toggle="dropdown" aria-expanded="false"><i class="fa fa-heartbeat me-2"></i>Heart tones</a>
-    <div class="dropdown-menu dropdown-menu-end dropdown-menu-dark collapse" aria-labelledby="dropdownmenu1">
+    <div class="dropdown-menu dropdown-menu-end dropdown-menu-dark" aria-labelledby="dropdownmenu1">
         <button type="submit" name="normal_heart_sound" id="normal_heart_sound" class="btn dropdown-item text-wrap active">Normal heart sound</button>
         <button type="submit" name="split_first_heart_sound" id="split_first_heart_sound" class="btn dropdown-item text-wrap">Split first heart sound</button>
         <button type="submit" name="split_second_heart_sound" id="split_second_heart_sound" class="btn dropdown-item text-wrap">Split second heart sound</button>