Administrator can't pin stream item in main stream

Hello. I noticed problem when "Administrator" (Joomla user group) try to Pin post in stream.
It works normal with SuperUser but not good with "Administrator":
1) login as Administrator (to main dashboard)
2) create test story post
3) pin this post
Result 1: item is pinned and we can see -------"Pinned Items"------- and -------"Recent Activities"-------
4) refresh page
Result 2: There is no more -------"Pinned Items"------- and -------"Recent Activities"-------
This pinned post will move down if somebody will add new stream item.
Seems system think that this post still Pinned because if I press on "^" icon, I can see "UnPin this item".

Thanks.