MarketPress Coupon Codes

I've got this issue with MarketPress Coupons. When assigned to a product it only shows posts and no products. if I type the product name in it says no match found.

so I went to staging and started plugin conflict test and It turns out that it's Divi theme. When I have all plugins deactivated the issue persists, when going to default WordPress theme it works fine.

Store -> Coupons