Cloned apps exist in an entirely separate instance of Android. This means that cloned apps which need information from the primary instance of Android on your phone such as your Contacts may not be able to access it.
You may be able to resolve this issue by enabling permission to access your contacts via your device's settings in Apps > Multiple Accounts > Permissions > Contacts.
If this doesn't work, or the setting was already enabled properly, we recommend adding your Contacts app to Multiple Accounts alongside the cloned app you need to access it with. This adds a copy of your Contacts to the instance of Android where your clone resides, allowing it to access that information.