New iPhone XR - Outlook contacts won't sync

I got a new iPhone this week and after three hours in the Xfinity store with employees who generally don't know and don't care, and four more hours with three seemingly knowledgeable tech guys at both Xfinity and Apple (and one girl at Microsoft who wouldn't talk to us on a conference call because she doesn't help people with free apps) my iPhone XR will still not recognize or display my Outlook contacts.

The guy at the Xfinity store downloaded the Outlook for IOS app, specifically designed to allow Outlook to work "seamlessly" with one's iPhone. The mail portion works fine on my phone, on my phone Outlook shows all the contacts, updates when I update a contact on my desktop, even allows me (I found) to make a call from that contact list (so despite the four keystrokes required, at least I no longer have to carry two phones with me - one for contacts and the other with an active SIM card). But (the problem is), when I press the phone key to make a call and then press "Contacts" there is nothing there. When someone on my Outlook contact list calls me, their number shows up instead of their name.

After four hours you can be sure we reset settings, deleted and restored the app, and twenty other things.

Has anyone else had this problem - and found a remedy - with Outlook mail contacts not pairing with their new iPhone?