When the mouse cursor hovers over the name of a dropped item, then a tooltip appears, showing its implicits and affixes. As soon as another item drops, regardless of whether it is filtered by the loot filter or not, then the tooltip window disappears. You have to move the mouse cursor somewhere else and onto the item again to show it.
This bug won’t be relevant (or noticable) for most classes, but if you play a Necromancer that let’s her skeletons do the dirty work while pillaging behind them, then this happens quite often.
This happens with controller as well as mouse. I play on Linux.