Change the default group for the "To" button in an email

New to 365 after years on 2007.  Just opened an new empty note and clicked the "To" button to select a contact.  But what I get instead is "Select names: offline global address list" with two options:  "All company" and my name.  In order to get to my contacts, I have to go over to "address book" and change that from "Offline Global address book" to "Contacts" to see my contacts. 

I don't know what "Offline Global address book" is, but i can't imagine I'll ever need it.  Is there a way to set that To button to always default to "Contacts"?  Thanks!   - Milo