This happened to me on day 1 of mangler. It will probably never get fixed due to how rarely it occurs
This has happened before on a few other TLPs. Happened to me when I rolled on Coirnav. None of the duplicates are valuable items. If you got a few extra backpacks out of the deal, that saves you what, a couple of plat down the road. It's not really a trivial bug, however, since I'm guessing it's in their netcode that communicates with the character database. It means that in a spike of extreme lag, other items being added to your inventory, say during a raid loot distribution, could also potentially be duplicated. It's funny how nobody has ever reported that happening.
Least you won't go hungry for a while & you can definitely see where you are going with all those lamps.
This happened on Coirnav and Selo as well. Not sure on the others but assume so. Was nice randomly getting 8 bags to start with.