It actually isn't fixed because this happened to me only a couple of weeks ago (with the next gen upgrade). But it must be an incredibly rare bug because I've done the "loot before cutscene trigger" a bunch of times before but only once did it glitch.
Avoiding spoilers, one of the major quests has you approach and help someone fight some monsters. In that same place there is a skeleton with a key in it for a different side quest.
After you finish fighting the monsters, a dialog cutscene triggers with the person you just helped, but there is a small window of time between the combat ending and the dialog cutscene starting when you actually loot.
I actually managed to soft lock a side quest in The Witcher 3 recently. If you loot a container right as a cutscene begins, the item will be removed from the container but not put into your inventory.
I managed to do this with a key (by mistake) and almost lost around 25 hours of gameplay lol.