Ok, each time I play to get thane of Falkreath, I never get the radiant "favor" quests... so I always have to "setstage favor258 20" to become thane.

This time, Rayya was not offered to be my Housecarl. I've tried resetting the quest stages, but that didn't help.

Is there a quest I should reset to be given Rayya?

there is a bug that keeps the favor fetching quests from triggering if you have a fetching item quest open from say Morthal. It might be fixed with the unofficial Hearthfire patch.

I have all Unofficial Patches up to date and can confirm they do not fix the quests (or if they do not fix them on an existing character) from not triggering if you have a similar one. Certain favor quests overlap and are technically counted in game as the same quest given by different people. For instance with me I have had the deilver Angi's letter to Skald for a hundred hours or so (have yet to discover Dawnstar..... at level 74) and as such can not get Idgrod The Younger to give me the quest to deliver the letter to Whiterun about her brother.

so those don't fix it? I know I could not become thane of Falkreath due to the fact I had a book fetching quest from the alchemy woman in Morthal. That was before I used the patches.