My galleries have changed to two columns and I cant find the reason?

I was messing with my site trying to install feedburner when I noticed all my next gen gallerys have gone into two columns! I have uninstalled feedburner but cant seem to fix the columns. It is responsive so it is one column on a smartphone, 3 on a tablet and 5 on a screen. PLEASE help it’s at https://www.paulmusso.co.uk

https://www.ads-software.com/extend/plugins/nextgen-gallery/