Have noticed this over the last few days.
I have been collecting quest item drops while in a group. I know that normally for the orange quest drops while ina group it goes auto into backpack and doesnt open the bag. The issue is that it is not going into my BP at all on some occasions, and I find I have to get double the amount of items to fulfill quota.
Other members are nowhere near and are telling me they are not getting items in their BP either so not sure who is getting all my items, lol