When you add a username to the field “Add owners” in group settings, the username then appears with an X next to it (see screenshot below). This conveys the impression that when I click “save” to save the group settings, the user(s) I just added will in fact be added to the group. Unfortunately, this is not the case. The added users are only saved if you click the “+ Add” button below and then click save. I think this is misleading and could be improved so that either the “+ Add” button click is not necessary at all or it is made more evident that the button has to be clicked before saving. But even here I see room for improvement.
In the field for adding members to the group right below is, the UX is slightly more intuitive: as long as there is no new member to be added, the “+ Add Members” button is greyed out. Once you enter a user name it becomes active and the attentive admin will notice that change and guess that “maybe I have to click “Add Members” before I save.”
Taken together these two issues make a third issue, namely that of inconsistency. Adding owners and adding members is almost the same thing (from a user perspective) so why should the UX be so different? (Note also that for adding members, there is no “enter username” hint)
And while I’m at it, it might be useful to add a hint whether owners are automatically members (i.e. owner = privileged member) or whether owner and member are two entirely distinct categories. I suppose that the latter is true, but it could be mentioned right in the rgoup settings where the question is likely to come up.