Missing drop

Hell hi i was playing the game and was testing the reliquary chests after update 0.21 and I looted an astramentis amulet and I was so excited i went to go tell my brother and then when I tried to town out it wouldn't let me town due to some instance issue and then it disconnected me and when I checked my inventory the amulet had disappeared when I logged back in can you please help me im just in shock right now idk what to do please let me know thanks. I'm very upset...