When activities are grouped, and thus already no longer in a strict chronological order, it seems counter-intuitive to me that:

the "root" of a group's branch is the most recent change, and not the oldest; and¶

the changes, when read naturally (top-to-bottom), are listed in reverse chronological order.¶

My suggestions:

Reverse the order of activities within a group; so the oldest of the related changes is at the top, and we can read the related changes from top-down, as is generally normal/natural/intuitive. OR;¶

Position the "root" of the group at the bottom, rather than the top, of a group. This way all later changes appear to "branch out of" the earliest, but keep their most-recent-first order.¶

(I personally prefer the former)

Additionally:

• Perhaps also a nice idea to have the "root" item of each group's tree show the actual "root" issue/wiki page/news/etc., rather than the earliest change that day? This could also allow removal of some duplicated information - project name, issue subject, etc.

• Perhaps another view should be added, for a strictly-chronological activity view (entirely ungrouped; as it used to be)? Since I can see there might be a desire for that - which the current grouping configuration already somewhat disrupts.

I've attached an image of what I mean, in case my descriptions aren't clear enough.