When a user adds a suggested article to a list (e.g., marking it "for later" with the star, or adding a whole collection to their personal lists), it is not clear where the items went. From the user perspective, the items just disappear and it is not immediately obvious where they went (since the personal lists at the top of the page may be out of the current viewport. This happened for several users during the research sessions we did for T119087.
As a possible solution, showing some feedback confirming that the item was added to the list would be helpful. If the affected list is inside the viewport, highlighting the added item may be enough. If the list is outside the viewport, a notice placed and/or pointing to the top may help to communicate that something happened above the current viewport.
This prototype illustrates a transition (when you add the "Lion" item for later by clicking on the star). The information element is shown coming from above (where the lists are located). This is a loading version of the usual information banners, as proposed in T67984. For a quick impression, check the animation blow:
