I could confirm the issue and it will be resolved in the future version of the plugin.

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

form.is-form-style.is-form-style-3 input.is-search-input {
    border-right: 1px solid #ccc!important;
}

I hope you are well today and thanks for posting here.

Could you please share the page URL from your site where it is displaying so I can troubleshoot it?

Best regards,
Ivory Search Support

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:

Click to leave a review

I’d appreciate that. 🙂

If I can help you further, please don’t hesitate to ask.

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

Your custom CSS code is wrong and needs to be redeveloped.

Also, to make the required changes you have to develop more custom CSS code and add it in the Custom CSS option of Ivory Search plugin settings on the path Admin Area -> Ivory Search -> Settings -> Settings

If you are not a developer, you can consider hiring a developer to develop it. You can hire a developer from any freelance site or WordPress agency.

You can also consider hiring me to develop it for you using the form https://ivorysearch.com/custom-work/

Best regards,
Ivory Search Support