Quest Horn of Vastir parts not in inventory

Horn of Vastir parts not in my inventory,

I killed the bosses and looted them but the quest items never went into my inventory.
Now the only quest I have is to get the Horn of Vastir from town but I cant.

I have killed bosses again but no quest item drops now.

I was having alot of internet problems and I think I somehow got lag and maybe the server thought I got the items but they didnt actually show up in my inventory.

I am now bugged and can not progress any further, rip druid.