Outlook 2013 and exchange. Cant see new mail in subfolders

In our company we have exchange 2010 with sp3 and all clients with windows 8.1 and Outlook 2013. Problem is that clients have problem with new messages in their mailboxes. they cant see new messages in subfolders. In Outlook 2010 everything worked fine, and after migration to 2013 this problem started.

For example:

There is user mailbox. He have a lot of subfolders. All subfolders is for varies companies. So he created rules, then someone writes from campany, mail goes to its subfolder. Problem is that then user opens Outlook in the morning, he can't see that new mails are arrived to those subfolders. User must open that subfolder and only then, inside that subfolder he can see unread message. But how user can know, that inside is unread mail? 🙂 Sometimes everything works fine, and sometimes user can't see new mails. Then he opens OWA, all new mails is marked as unread and there is number near subfolder with unread mail count.

And this problem repeats to all users. I updated exchange to SP3 update 6. Operating system and Outlook is up to date. Recreation of profile helps for a week or two (Or user do not notice problem), and after that user calls me again with the same problem. And this happens not for one user but for all. Sometimes restarting Outlook helps, after restart number with unread mail count appears near subfolder. There is no addins or other changes in Outlook. Search folder is not a solution, because there is a lot of subfolders, so it would be a mess.

Can you advice me? Where can be problem? Is it global for all users who are using exchange 2010 and Outlook 2013?