Switching to a channel with unread messages displays historical chat instead of scrolling directly to the oldest unread message.
Steps to reproduce
Use the mouse to select a channel with unread messages.
Alternatively switch to a channel with unread messages by using the quick channel switcher accessed via Command+k.
After the channel switch occurs, observe the contents of the channel’s message display and compare to the results listed below under expected vs observed behavior.
Additional notes:
This occurs for channels where you just read the newest message seconds ago.
This occurs for public and private channels as well as direct messages.
This occurs with Mattermost desktop client v4.4.0 and server v5.19 (it occurred on prior versions as well).
This issue does not always occur on every switch, but is frequent enough to impact productivity.
Expected behavior
When switching to a channel with unreads, the window should scroll down to the oldest unread message for your initial view.
Observed behavior
Sometimes when switching to a channel with unreads, the window will display chat messages which have already been read several days ago. The top of the message window includes three animated horizontal loading dots and no subsequent change occurs until you take action. At this point you can scroll down to reach the unread messages or apply the workaround referenced below.
Partial workaround
Jumping out and back into the channel displays the newest message as all messages are now considered read. This is accomplished using keyboard shortcuts of Command+[ followed by Command+].
Here the behaviour changed after upgrading the server Linux distribution and Mattermost. We are now running nginx 1.14.2, Mattermost 5.20.1 and the channels do not jump back in time anymore. However, they get stuck in “Loading…” in the same situation when they would have been jumping earlier. In Chrome developer console these two Fetch rows seem to be in infinite loop. Or maybe not infinite, in this case it completed after they reached some 180 attempts and the channel content was shown.
Nope, not fixed. Cleared the caches and restarted browser after Mattermost upgrade, same behaviour. Unread channels randomly get stuck in “Loading…”, waiting and letting them do some 200 cycles of those POST/GET fetches or switching to another channel and back fixes it.
By the way, it still occurs only on Chrome, mobile client at least is unaffected and Safari at least used to be unaffected. I will test for a while with Safari to confirm.
There’s a firewall device between the users and the server by the way, a Juniper SRX with default timeout values. It does allow all the traffic, but it does kill idle sessions after timeout. That could be related or then not.
Thanks very much for all the responses and relevant links! Hopefully we can isolate the root cause and resolve it permanently.
I’ll try using firefox/safari as an alternative. The main feature I am missing in that scenario is the very useful desktop option: “Show Mattermost icon in the menu bar” which greatly assists indication of messages with the red vs blue dot.
What version are you on @LittleBobbyLikesChat. I can give a custom build with the fix on top of your existing version. If you @stnz or you are interested in verifying it.
I can try to build too. Maybe a bit too early for conclusions as our chat is rather quiet in the evenings, but I haven’t seen the problem occuring yet after setting Chrome zoom to 125%. Tomorrow I should see if it still keeps occuring.
