I am attempting to use the /rest/api/2/user/assignable/multiProjectSearch API in jira server (version 8.13.4) to return a list of assignable users.
This API returns an empty array of results regardless of what is passed in (i.e. project keys, usernames, etc.). I have checked my user permissions using the /rest/api/2/mypermissions API, and the value for permissions.USER_PICKER.havePermission is true.