Hey Mauro,
I’m not sure about the style issue. The gallery display looks fine to me.
Regarding the lightbox issue, it’s because of Envira Gallery’s caching. The feature looks unstable. Sometimes it works, sometimes it doesn’t. Take a look at the screenshots below using the same gallery and unchanged settings.
##Home Page
##Test Page Working
##Test Page Not Working
I’ll submit this to our issue tracker so that the person managing the third-party plugins could relay this to the Enivra Gallery developers. This would take some time though. I saw that you’re using a standalone license of Envira so it would be best you ask for support directly from the developers.
Thanks.