Customizer settings over-ridden by style css

For example, setting the primary navigation font to uppercase in customizer doesn't work and the style css default over-rides. If I manually change it in the customizer's additional CSS then it will work.

I'm using woocommerce, a child them and it's a multisite. Pretty sure I still had this problem on a single site (still using woocommerce and a child theme).

Any pointers?