Poison or soda, bug maybe ?

[Wonyo]

Hi all,
I'm trying to complete this task, there is one last spot that is maked in yellow in the quest chain.
Now, when I get there, I get the juice thing, throw it, beasts approach, but immediately disperse before consuming it.
Happened to anyone ?

[EDIT]
I "finished" the game in between (full upgrade Javelin and got credits), and on next reload, this worked!
So something was borked in the game, but somehow fixed itself...