Posts don't appear synced between browsers - I'm logged in on FF and can see up to post 6823 in the dangerous drivers thread, but logged out on Chromium and I can only see up to post 6821
When you are signed-out, you are viewing the cache.
When you are signed-in, you are viewing the very latest items available.
The cache for those signed-out, is set to 300 seconds = 5 minutes. This means that at most, conversations may be 5 minutes out of date if you are not signed-in.
Posts don't appear synced between browsers - I'm logged in on FF and can see up to post 6823 in the dangerous drivers thread, but logged out on Chromium and I can only see up to post 6821