Remove the social share sharing plugin and replace your current caching plugin with WP Fastest Cache plugin (free). That should fix it.
George, thank you very much for your assistance. You have been very, very, very helpful. The fact that you try your best to offer the community support even though it’s a free plugin amazes me. You should consider offering paid annual support subscriptions and integrating XML sitemap to the plugin. This is a great plugin and deserves every 5 star it’s received. I think it’s the highest rated SEO plugin on WordPress. Congrats! Customer service in America is highly valued. Cheers!