Taliesin Quest Bugged Merged

Taliensin's quest is bugged for me on the fourth riddle. I have completed the Bastion of Might quest, that separate quest now says, "answer the fourth riddle" but when I speak to him, he says "A jest I hope, no riddles will be given until my ballads have been found"

I've tried leaving and coming back, sleeping, even remaking the realm, none have worked.