Strange, but it seems that Instagram blocked your server’s IP because of too many requests. Now you need to disable the Instagram for a few days. Try to use images gallery instead while it is blocked. Unfortunately, there is no way to fix it from the theme side.
Thank you! I removed the instagram feed from the entire site. Should I expect in the future this thing to happen again or not? Because what is the point of having an instagram feed if Instagram blocks you.
At the moment, we don’t have any information about this because Instagram didn’t block anything in the past. Wait a few days without adding the instagram element to your pages and then check again.