I have seen threads about this problem and I have it too, the only difference is that the users experiencing this problem have a second or shared mailbox added in Outlook. When I remove the shared mailboxes, then the issue goes away. I have checked to make suer the user is the default, but does not make any difference

I recommend you open an incident with Microsoft Support if you feel you've found a bug.  Before doing that, be sure you're running at the latest cumulative update level and reproduce the problem on it.

Hi,

According to your description, I understand automatic reply can't work on some specific users.

Please confirm if the issue also occur on OWA.

If it can work on OWA, the issue is related to outlook side.

Please try to create a new profile to test for those problematic users.

If the issue persists in OWA, please run the following command to check your server setting :
Get-WebServicesVirtualDirectory | FL Identity,*AUTH*,*url*

Regards,

David 

The issue does not happen with OWA so I have told my users to use OWA till the issue is solved. Creating a new profil for only the default user Works, but when the shared mailbox is added then I get the problem.

Hi Petro,

Are you using IE proxy server? If yes please remove the settings to none and test.