Child theme css changes won’t work without !important

I’m using the Vantage theme – really liking it so far! I’m making quite a few customisations, so I used your child theme starter to create a child theme.

I’ve made a number of changes in the child style.css, but they don’t show on the site unless I use !important for each change. I’ve never had this problem before with other themes.

Any ideas what’s causing the issue? I guess it’s something to do with priorities, but I thought child style.css was always given priority over the parent css?

Thanks