I am using Civi 4.7.27 on Wordpress 4.9. Today while trying to compose a new civimail message, I noticed that the recipients field is not automatically finding recipients like it used to. We recently upgraded to the latest version of both civi and wordpress. Is anyone else having this problem? See screen shot for details. I hope someone can tell me what I need to do to resolve it.
Problem solved. After installing the civi upgrade, I needed to flush the cache by going to Administrater/System Settings/Clean up Caches and Update Paths then click the Clean Up caches button. The issue was resolved immediately after doing that.