Periodic hang of sending messages

From time to time, the sending of messages in the “chat” hangs, sending out messages does not work at all. But at the same time the mathematics itself looks working and only the actions associated with users stop working (for example, creating one-on-one chat, you can select a user but you can not press Go)

Debian 8.7
CPU 12 core
PostgreSQL 9.6.1

Mattermost 3.8.2

Hi @danilvoe,

Could we have your help upgrading to the latest version of Mattermost to see whether the issue still reproduces for you? v3.9.0 shipped on May 16th.