Exchange 2010 and Exchange 2016 Co-Existence

I have Exchange 2010 and Exchange 2016 in my environment. I will be running them in co-existence mode soon, with the single name space pointing to Exchange 2016 (mail.domain.com). I'm currently testing by using a host file on my laptop, and the host file has the name space pointing to the exchange 2016 servers. The question is the following :

I created a mailbox on the 2016 environment and opened it  in outlook 2013 and everything looks good and the MS Server text box under properties in outlook shows the following 4db9c442-353c-46c4-a602-1276a06cb47a@domain.com as the Microsoft exchange Server, which is correct since 2016 uses Mapi/Http. Now i have also moved my personal mailbox over to Exchange 2016 and the everything looks good and its working correctly but the issue is this: Under the properties in outlook the Microsoft Exchange server shows the name of our CasArray for Exchange 2010 instead of the Exchange 2016 name like the other mailbox. I logged onto another computer and created the outlook profile again and it shows up correctly for 2016, but if I go back to my laptop it shows the CasArray name instead. I completel deleted my outlook profile on the laptop and rebooted, opened outlook and allowed outlook to recreate a new profile, and it created fine but it is still showing the CASArray name. When I look at the connection status it shows the HTTP protocol which is correct and it shows the single name space which is pointing to the 2016 servers, so not sure why the CASArray name is still showing. See pic.