I did some testing with your installation as well as our demo site. This is just the behavior of the browser which navigates to the element right but the sticky menu – which has position fixed is ignored (basically the browser is unaware of it’s existence since it is marked as position fixed in CSS and takes it out of the document flow). Only way to get around this is to have a small padding for the element. So, if you place the following Custom CSS in the theme options –
#test-1, #test3 {
padding-top: 92px;
}
you will notice that the navigation is ok. You will need to find a workaround this way. Hope this helps.