Unlike most I enjoy liking the progress of the people I follow and encouraging them. But due to my activity bug which hasn't been showing all of the activity, I can't. For example, when I click on one of my follower's profile it will show their progress from months before which I never saw. I've noticed that it'll show the progress of my newer followers but not the older ones. Is it because if it did show all of the activity it would be too long? Has anyone else experienced this?
I can't answer your question as well as some others may, who follow more people. I have heard that only the progress of the last 100 people you have followed displays, so the more people you follow, the less activity you will see from those whom you followed earlier. That's why a lot of users select only 90-100 of friends and/or helpful users to follow and only follow active users.
As for the activity streams loading older activity, that's odd, but I've noticed sometimes the forums display incorrectly (in terms of times discussions were posted) so... Sorry I can't be of more help there.