Create Product Button not showing on BackOffice

[jose.indexeo]

Hello everyone. 
I am developing a multistore shop and I have a problem on adding new products. 
When a click on the add new product button on the product catalog the popup with the options appear.

Then, I choose the shop and the product options are shown (combination, individual,...); and here is the problem, there are no button to continue. 

I've looked in the browser's developer console and the button appears when I search for it using ctrl+f. The funny thing is that it also appears in the popup when I perform the search.
I have tried to add CSS styles to make it display but there is no way.

 

Popup before searching on the console:

Popup after searching on the console: