Hello,
Do you mean Theme Options > WooCommerce (Shop) > Product Catalog > Products Per Row? Have you clear cache? Do you use latest versions of the theme, Core and WooCommerce?
Try to disable all the third-party plugins, that do not come bundled with the theme https://www.8theme.com/documentation/xstore/plugins/included-plugins/ , and check how it works then. Let us know the result.
Regards















