iphone 7 - emails always marked as unread

On my brand new iPhone 7 running ios 11.2 and brand new iPad Pro running 11.1.2 I am having an issue with my Exchange account in the Mail app. I can receive and send emails, but my problem is that emails I have already read on my computer (Windows 10 running Outlook 2016) do not ever mark as read on my iPhone or iPad. So I end up with a bunch of emails at the end of the day showing up on my iPhone and iPad when I actually read most or all of them while at work.

I have tried: turning off "mail" via settings>accounts and passwords>Exchange and then restarting or doing a hard reset on the phone and coming back here and turning mail back on. When I do this, it updates the unread emails accurately, but it sure would be nice if I didn't have to do this every time I wanted to know what emails I still need to get to in my queue.

I have also totally deleted and reinstalled the Exchange accounts on both devices a few times. When they are reinstalled they start out with the correct emails read and unread, but slowly as the mailbox gets new emails on my computer, the problem returns on my iPhone and iPad.

I suspect this has something to do with the Exchange Server or ActiveSync settings for my Outlook email account, but the IT folks at my employer have not helped me with these settings. Apple will not help me either and says these settings are the issue.