Thanks for taking the time to help me.
I have installed Slider Rev and all is working fine except for a small aesthetic.
Im using a template (this HAS the white border) – https://revolution.themepunch.com/wordpress-portfolio-plugin/
BUT the white border that is failing to appear on MY front-end.
When un/installing the plugins – it didn;t resolve.
when changing the theme it did resolve.
I’m not sure whats happening.