Home page grid disappears after new postings, then after some time, it reappears

Hello.

I am using 2014 theme to revamp https://peliorama.gr/. The problem is that every time I make a change, e.g. update a post or publish a new one, the grid disappears from home page for a while. Everything else stays there, the sidebar, the menu, the static front page, etc. It’s just the grid with the featured posts that disappears.

Then, after a while, it appears again. How can I fix this?

Thank you.