problem with shipping methods

hello people, I'm desperate .... I've been with this for days and has no head or tail ... I have several geozones, one from Europe and one from Spain, the one from Europe gives some prices through mrw (which is not more that put price to the weight, use the module of price by weight) and the one of Spain flat rate, now comes the rare thing, there are products that when they are added to the cart and then it goes to the checkout the list of options appears but others cause that it appears the message "there are no shipping options available" and nothing appears ... I compare a product of which if they make the list of shipping options appear and another that causes the message, they are exactly the same, the only thing that changes is the text, model and price, the weight have the same, this is all the same, but when I pick one in particular I get "no shipping options available" and it's driving me crazy ..... I use the journal2 theme with the opencart version 2.3.0.2
You can check it here: http://soundonseteurope.com
look for a product called zoom H2N, that if you get the list of options at this zoom f4, which does not allow the list ... it brings me upside down and I do not understand what may be happening

Your description is extremely confusing. A couple screenshots would serve much better.

thanks for respond, sorry but the screenshot would be in Spanish, only tell you about the problem, Depending on the product, shipping options are shown or not...this is crazy....If they compared a product that does not leave the options with one that does, the only thing that differs is the name and price