Back then it looks like a browser switch resolved it - not sure if Chrome is still an issue with this one? However, in our case, three newly-added owners of the flows have absolutely no entries at all when viewing the activity page:
@psycrkz1 sorry, I should have been clearer. They are new owners relative to me, but not that new. I added them all last week (or maybe the week before) and they have no activity at all (and there is daily activity visible to me).