Using Ultimate Pro 3.0.1. The background images in the Promo Boxes don’t seem to respond on iPhone/iPad – in Safari and Chrome (didn’t test any other browser). Instead the images zoom and look more like a blob of color instead of filling the width with the full image.
You can see it on the theme preview site https://www.themehorse.com/preview/ultimate-pro/ if you use an iPhone/iPad. It doesn’t do it in Safari/Chrome on MacBook Pro when resizing the browser window though.
It was due to the background-attachment is set to fixed. So, Please login to your WP dashboard and go to Appearance > Customizer > Design Options > Custom CSS and add below css code: