I've noticed that it is not possible to float topics in the activity section of a group hub page. You can select a forum topic and float it, but it will not appear at the top of the list in the group hub activity, only if the user navigates to the forum section itself. This means that there's no way to float an announcement or welcome topic on the first page users are likely to land on when navigating to a group hub. why no floaty?
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