I have reset my Strange Favor rank a number of times, I have lost count. Every time I log into Destiny now, I am presented with a splash screen telling me I can Reset my Strange Favor rank. Except I can't. Every time I go to Xur, there is no option to reset or even a reputation tracker, I can only pick up bounties. Same thing for Star Horse. Is this a bug or are you only supposed to have a certain number of resets?