Duplicate main menu bar

I suggest seeking support from the theme developer.

Try to open header.php file via Appereance > Theme Editor in your website dashboard. Find this code <div id=”main-nav” class=”main-nav”> are there 2? If yes then you must delete one of the code with all its child elements.

If you can’t find it, then you can force hide via CSS code. Open style.css via theme editor and find this code:

#menu-header, .menu {
max-width: 960px;
margin: 0 auto;
}

then add this code below the above code:

#main-menu-1 {
display: none;
}

I have try to fix a similar case on my site paket wisata jogja and can fix it successfully

Thanks for your suggestions syafira5 – I have checked and my theme seems to operte in a different way. Although I can see the offending code in ‘Google Inspector’ I can’t identify the file that is generating it. The theme header.php file doesn’t have the code in it. Also the style.css file for the theme doesn’t have the code you illustrate in it either.
The theme is ‘Responsive’, and it is a child theme that is used.
Phil