Quest "Order Up" Glitched

I am working on the quest "Order Up" and when I attempt to talk to Grevan to have something checked for the Library for the Order of Janniston, all that he replies to me with is "Mistress Svenja is quite busy researching a new type of medicinal concoction. I'm afraid it will be a while before she is able to entertain visitors."

I have asked in game if anyone else has this issue and I got a reply that it might be because I have completed the quest, "Flowers for Svenja".

Now how am I supposed to complete this quest?