For now, all that we know is that we are Movistar clients, my gf is Vodafone client and she can see the skins perfectly. So we can assume that is a Movistar issue.
Bombardeen Movistar
TELEFONICA DE ESPANA S.A.U.
It's not duplicate, I see one of the default models.
Now that i reinstalled and reboot my PC, now I can’t even see my friends skins neither, any random default skin is shown aswel.
@Greymagic27 I’ve been talking about this in the “Movistar“ forum (Movistar is the company that provides the ISP that is causing the problem) and someone said that might be because Mojang load the skins with http and not https, and could be something different of a ISP error.