If you are are talking about the little purple boxes with the bows, I have seen that too. It's been going on for a long time in my game, so it's not due to a recent patch. I'm not sure when it started but I do know it was happening before DU. I happens only when I play a lot in that zone or spend a couple of days visiting in the zone without leaving so you have to be in that zone for an extended time. I think they spawn once a day so you have to be present in the zone for a couple of days continuously for it to happen. I've only seen it happen in the BB zone where the big lot is too but I haven't played in the other two zones for any extended time so it may happen in the other two residential zones but I just haven't seen it. My guess is that it probably does.
If you don't collect the boxes very often, they will continue to build up at their spawn points. I don't think they are connected to your pets though. Mainly because I don't play with pets since they take up a household slot and I would rather have a sim. I have seen them spawn a time or two as well if I happened to be standing near one of the spawn points when they spawned again so I don't think are connected to the strays either. They are more like the dig rocks imo in how they spawn.
Anyway, I agree that once one spawns, it will remain at that spot until you pick it up. Never goes away like the dig rocks and frogs do at times in other worlds. And if you don't collect them, they will spawn on top of each other. The longer you wait, the deeper the pile gets. Visually, the pile looks like one package, but they are stacked on top of each other and any number of packages can be there. How many are there depends on how long it's been since you lasted collected them and there may be several piles around a single spawn point. So if you pick one up, then it looks like it's still there, so you keep picking them up until they are gone. I never had 30 that I can recall, but I've had at least 10 or so in a single pile on occasion. I kind of like it though since they can give you all kinds of collectibles. One of the little bugs that actually works in the player's favor.
But it is only the little gift boxes. The feather piles don't do it.
Btw, I play on PC.
Hope this helps.
