Why does Outlook 2016 freeze with an Exchange ActiveSync account?

Question

Outlook

Outlook 2016 hangs systematically. The account is connected via Exchange ActiveSync to Exchange 2013.
Hangs during Reply, Forward, Compose email operations. Tested on several systems including completely clean with the latest updates (win7, Win10) with the same "problem" account. You can only close Outlook through the task manager.
Exchange serves no more than 150 mailboxes, there are no mailing lists. Such a hang is about 5% of users, and only they. Most of the users have never seen such freezes of Outlook. If you do not touch Outlook when it freezes, then it does not come to life itself, does not go offline, and the like.
Could Outlook 2016 hang due to broken Exchange connections (firewall, connection hijacking, or something similar)?
Errors respectively are not written anywhere.