css – The menu toggle only works on some pages of WordPress

I'm using a custom WordPress theme expanded from Twenty Sixteen for this site. He uses Bootstrap (I had to migrate a static Bootstrap website to WordPress).

If you open the site on the mobile, only the The menu button on the homepage is working properly. However, if you are navigating to any other page, the menu button does not go down. I'm using the same template (index.php) for the homepage and all other pages. The HTML and CSS code in "Inspect Element" looks the same, and the JavaScript files are also identical.

If it works on the home page, I can not understand why it does not work on other pages. Here is the link to the WordPress website: https://www.unityinfinity.com/ui

Thank you for your time!