Why landing page doesn't appear ?

I don't know why in local my landing page (AVADE THEME by Twizanex) works fine while with site online on the server the Landing Page doesn't appear but when I log out of site I see this  https://ibb.co/eXPU4y

How can i fix it and see my landing page ? I have tried other theme but the problem remains.

So I think it probably depends by some plugin that show the registration form instead of the landind page. But I don't know...

Anyone can help me ?

Really thanks, I miss only this for finish my site.