Possible Plantera bug?

[Stippler]

On a multiplayer server we defeated plantera multiple times. We killed all mechanical bosses as well obviously, but Truffle still doesn't sell the autohammer, there are no new mobs in the dungeon and we can't summon the golem either.
Did we miss something? Why doesn't our world 'transform' into post-plantera? We would really like to avoid creating a new world...^

EDIT: We fixed the problem by changing the hosts steam language settings from german to english and defeating plantera again.

[Rachter]

It seems like the game didnt recognize Plantera was killed. Unfortunately this bug doesnt seem to be on the Terraria Wiki, so I have no idea how to fix it, try Creating a new world, or defeat plantera on the same world but on singleplayer.

[Stippler]

fixed, see edit

[Rachter]

Oh yes, Terraria still has some problems with the languages, English works best for everything. Glad you fixed it.