1) Appointment Pro
2) No, I am not using any menu plugin
3) I tried but no impact
4) http://www.highpinestc.com
5)
Initially I created the menu from Appearance > Menu but now I can’t see the menu that I have created. Therefore, I am not able to make any changes anymore.
Then I tried to create from Customize. When I create new menu it is ok, but once I get out from the Customize > Menu page, the menu that I have created will disappear. Therefore, I am not able to make any changes anymore.