How to set the spacing between columns on a Wix Pro Gallery

My desktop site has a scrolling gallery with one line of logos. On my mobile site, I’m converting the layout to be two lines to fill the space better, as per screenshot below. There’s a huge space however between each of the lines, how do I reduce this?

Mobile:

Spacing only adjusts the size of the logos within each line - NOT the padding in between the lines.

Any help greatly appreciated!

For context, this is the layout on desktop.