We know about and are currently investigating an issue some people are having regarding updates not getting delivered consistently.
Our big infrastructure move recently has done wonders with respect to maintaining a reliable service during shared events like the Super Bowl and Super Tuesday. However, we are still fixing bugs related to the move.
We’re tracking the missing updates issue now as a team and we’ve made some progress. The updates are in our database so they’re not actually missing—the problem is in the delivery. Our support team can manually clear individual timeline caches to temporarily reveal some of the ‘missing’ updates but that’s obviously not a real fix.
We’re getting closer to the answer. To the people who are experiencing this issue, thank you for writing in to support and Satisfaction. We are aware of it and will keep you posted.