Our monitoring systems have identified a performance hit when upgrading to the latest version of the WordPress SEO plugin by Yoast. Further testing shows the 7.0.2 version increases the time to first byte by 50%, with reports of others experiencing similar slow downs when upgrading from 7.0.1 to 7.0.2.
We recommend avoiding upgrading to the Yoast SEO 7 branch and to 7.0.2 until these issues have been fixed by the plugin developers.
A popup message has been added to the plugin screen for WP Charged customers to warn users about this issue.
Update 13/03: Yoast 7.0.3 is still affected by this slow down
Update 14/03: A fix has been added and will be available in version 7.1 due for release on 21/03.