Outlook for Android not syncing contacts automatically

Hi Everyone,

I can't get Outlook on my android phone (Samsung S9) to sync contact automatically with my Exchange (Microsoft Hosted Exchange) account.  If I add a contact on the Outlook app running on my Windows 10 laptop, I can see it if I look on the Outlook for web.
I have checked the usual settings on my phone:

The only way to get the contacts to update is to reset the account:

Contacts that I add on my phone (Exchange account) do not sync back to the online account.

Outlook on my phone syncs emails with the same account normally.

I've tried clearing data / cache, and even taken the extra step of uninstalling and reinstalling on my phone but it makes no difference

Any suggestions gladly welcomed!