Thank you for using Connexions 2. As mentioned in the description of this app on App Store, Connexions 2 displays contacts and groups only in the default account. To set the default account, go to the Settings app > Mail, Contacts, Calendars > CONTACTS > Default Account. Please be sure to check the setting. If the setting is not displayed, you don’t need to set the setting.

There are Default Account settings of Mail and Calendars in the Settings app > Mail, Contacts, Calendars, so please don't confuse them with the setting of Contacts.

If you set the default account to an account of Google, please be sure to read When you set the default account to an account of Google.