I just recently upgraded to Civicrm 5.9.1. I had used the Mailchimp extension in the past in test mode previous to our current Civicrm upgrades, and now want to implement it. I was behaving weirdly after the upgrade, so I uninstalled it and then reinstalled it.
I have the newest 2.0.1 version installed, the permissions should be correct since I've assigned all user roles to the Mailchimp: allow webhook posts, and I've verified the webhook is running (doing a Mailings -> Mailchimp settings -> Save and Test responds that the API is returning the correct information from Mailchimp). We're still running Wordpress 4.9.9.
When I attempt a manual sync in one of the Mailchimp sync choices under Mailings, I get a description screen, but no ability to do anything. Has anyone else seen this behaviour or have insights?
There's nothing in error logs that indicate anything is happening with PHP. We're running PHP 7.1.26.