Hello johnnyb50uk,
Thank you so much for purchasing our theme Corporate Plus Pro.
You can use only text slider or full slider, means background image will slide.
To use this options ,
Go to Appearance > Customize > Featured Section Options > Featured Slider Selection > Slider Type
Select the slider type Full Slider.
Hope, your problem will solve by this process.
If you have any query, please feel free to ask.
Best Regards,
Acme Supports