Problem with Search Function/Plugin

I’ve installed a basic search bar on our website, which works fine when it can find something matching your search… But when it can’t it brings up a completely different page, with the header all wrong!

I’ve narrowed it down to this line of code, <?php if (is_home() || is_front_page) { ?>, which I’m assuming means that it’s actually re-routing the search to a different page, rather than the actual home page?

I’ve tried changing and removing and adding loads of different things, and nothing seems to work. The plugin I’m using is Cyclone Slider (don’t know if that’s part of the issue or not).

Does anyone have any experience with this, or could you help at all?

Thanks in advance x