im having the same problem in riften, i bought the house and did every quest for the town but no way to become thane, my quest tells me to return to the jarl, but when i talk to her the "I BOUGHT A HOUSE AND MADE UR PEOPLE HAPPY" part isnt there!
I am having the exact same issue. I also bought the house, and returned to the Jarl, however there is nothing regarding completing the quest in the Jarl's responses. He does have the quest arrow above his head.
I have went back to him each time I visit Riften, but nothing has changed. The quest remains active in my misc quests.