WordPress Speed Up Service | WordPress Website Maintenance Packages Reply To: Anything in 4.9.2 that could cause MASSIVE slowdown – time to first byte?, by Steve Stern I’m not saying there’s some edge case that makes 4.9.2 to blame, but if there is a blame, it’s definitely not anything across the board. So…. time to see if it’s a plugin/theme interaction. Disable all plugins, and use one of the default (Twenty*) themes. If the problem goes away, enable them one by one to identify the source of your troubles. If you can install plugins, install “Health Check”: https://wordpress.org/plugins/health-check/ On the troubleshooting tab, you can click the button to disable all plugins and change the theme for you, while you’re still logged in, without affecting normal visitors to your site. Reply To: Anything in 4.9.2 that could cause MASSIVE slowdown – time to first byte?