Unable to read contacts in Microsoft Office 365 in debug build

I use CNContactStore enumerateContacts to read all contacts, https://fburl.com/9plmcenx

Surprisedly, I cannot get contacts synced from Microsoft Office 365 using this API from debug build, release build works.

I am wondering what might be the reason?

Contacts synced from gmail, or saved locally are read fine in both debug build and release build.