I need to fix opencart checkout onepage

I have a problem with Journal3 Theme for opencart and Custom Product Designer module.

If i use onepage checkout from journal3 theme, i have blank product (designed from costumer with module custom product designer ), no thumbs picture with the new design, and in admin panel order is blank product.

If i use standard checkout from opencart classic theme, all is good. But here is a lot of steps to finalize the order (personal detail , next, billing address, next, shipping address, next, payment method, next, delivery method, next .... etc, and finally place order.

I need to fix checkout onepage to display product with design (thumbs) and save correctly in admin panel (orders).
Thank you!