You can achieve this by adding the below CSS code in the Custom CSS option of Ivory Search plugin settings on the path Ivory Search -> Settings -> Settings

#Top_bar li.is-menu {
    padding: 0 0 0 20px;
}
#Top_bar li.is-menu a {
    line-height: 50px;
    background: #d2cfcf !important;
    padding: 0 15px !important;
}

I hope you are well today and thank you for your questions.

Could you please share your site URL where it’s displaying so that I can help you?

Best regards,
Ivory Search Support

Sorry to hear about the problem you are having.

It was an issue that is resolved in the latest released plugin version 4.5.7 so could you please make sure that you are using the latest version of the Ivory Search plugin?

Best regards,
Ivory Search Support

You are most welcome here 🙂

You are always welcome, I’m glad I was able to help you with this matter. There is no obligation but by your kind words I wonder if I could trouble you to leave a review based on this experience here:

https://wordpress.org/support/plugin/add-search-to-menu/reviews/?filter=5

I’d really appreciate that. 🙂

And if I can be of any further assistance please don’t hesitate to ask.