Because this isn't happening in your local development environment, I would guess it's not EE related but instead is caused by something on the server or is DNS related. Have you contacted your web host to see if this is a server related issue?

Because this isn't happening in your local development environment, I would guess it's not EE related but instead is caused by something on the server or is DNS related.

But here are some things to try/check:

• Log out of EE, clear all cookies and cache, then log back in
• Disable extensions temporarily by adding this to your config.php file $conf['allow_extensions'] = "n";
• Disable “New version Auto-check” in your Control Panel under Admin > General Configuration
• Uninstall the "ExpressionEngine Info" accessory under Addons > Accessories
• PHP error logs