I have done the prerequisites for Oboro and he will speak to me about weapon choices: thing is I already have a Sandung. I got it from the NNI drop event and I have been trying to upgrade it with the 300 pieces but Oboro keeps asking for the items to build a Sandung. I have tried everything- speaking to him with the item equipped, trading the pieces with and without the dagger, trading the pieces with the dagger equipped and nothing happens.

Is there something I am missing or is this a glitch since I got the dagger drop from NNI and did not actually acquire the items to build a Sandung?