We have an Exchange 2016 system on CU7 that is having an odd issue. When we create a mail contact, the email address does not fill in (see image 1). You can see the field is filled in on the contact (image 2). I am guessing this has something to do with the arbitration mailboxes but I think they are all good (image 3).
For these 'problem' contacts, we are unable to forward email to them due to this. Not sure where to look at this point - any ideas?