I found today a buried Marlin Drybag, it was buried but also desync on the Ground. I was able to pick up items from it, but not able to pick to whole bag up. After i relogged, the buried pile of erth was there, but the backpack was gone. I buried that bag later out and in the bag was nothing inside. So it was not a visual glitch that i picked up all the loot from a buried backpack.