Cannot retrieve some hidden stream items

Hello there and happy year,

I just want to report this:

I denoted that after hiding stream items that have file, link or photo, i cannot see them in Activity log (in Hidden activities tab). But it works fine for any stream item with text only; on my test site, i uploaded a photo and added "photo" as text, but in Hidden activities tab i see only the text "photo". In other cases (File and Link posts, without texts), hidden stream items don't appear at all in Hidden activities tab.

In additional, it seems that there is a strange behavior when hiding a stream item: this message appears: "item are now hidden from your timeline" and "Undo" link appears also just next. But when i click on "Undo" link and refresh the page, item is although hidden.

Help please