How to remove hover underline from custom navigation buttons

I don’t see any hover borders or underlines.

sorry, was playing around where I disabled it for all menu items. should be back up now.

#menu-item-1025 a:hover, #menu-item-1300 a:hover {
   border-bottom: none;
}

To add CSS:

• If you are using WordPress 4.7 or later, use the “Additional CSS” option in the customizer.
• If your theme has a custom CSS option, use that to add the CSS shown above.
• If not, install the plugin Simple Custom CSS.

Learn to use the Chrome Developer Tools to help you see and test changes to your CSS.

Hello @lukasz934

You can achieve this by applying following CSS code.

#mainnav ul li a:hover {
    color: #ffffff;
    border-bottom: none !important;
}

Hope this will help.

Thanks.