If you check this url: https://www.suministrosurquiza.com/boquilla-hidrolimpiadoratriple-karcher-hd-650 on webmasters tool, fetch as google feature, on mobile request it gets the page ok but if you do on desktop it get unreachable, and on other tool (https://aw-snap.info/file-viewer/) it says It looks like your site has returned a 500 Error. In some cases the firewall or a bad bot utility will block the use of this tool.
Why can it be? Could it be some cache error from the past? What I can't understand is why on desktop is no reachable and on mobile yes..