Summary
Desktop client users sometimes have missing posts until they refresh
Steps to reproduce
Happens unpredictably, currently with desktop client 1.2.1 / mattermost 3.2.0 but also reported with earlier versions. Might only happen after a period of inactivity (not sure)
Expected behavior
If posts are shown in a channel, users expect all earlier posts to be visible too
Observed behavior
Sometimes an earlier post is missing, and remains missing even on further user activity, until they do a refresh in the client. There is no indication of the missing post at all, and other users can see it, so users may not even realise they are missing one (unless surrounding conversation makes it obvious!)
On earlier versions I saw an issue where a newly-joined user's posts was invisible until next refresh, but the issue reported here can affect well-established users who were already in the channel, etc.