Combined CSS files

I am trying to do speed optimisation with SG optimizer. I am using “Product Options and Price Calculation Formulas for WooCommerce – Uni CPO (Premium)” plugin in my site.
If I enable the “Combine CSS Files” function, the form I built using the above plugin not showing the css styles for some products. for ex: business cards page is not showing the styles but the flyers and brochures working fine. But if I login to my wp-admin, everything works perfectly. It would be great if you can help me to solve this.

Thank you

The page I need help with: [log in to see the link]