Hello guys!
I bought my Xbox One almost one week and my first game was Forza Horizon 2 and later the Fast & Furious version. (Before that I had 360 few years ago and played Forza 4 with SAME M$ ACCOUNT)
I Downloaded the Forza HUB on my Xbox ONE (With same M$ Account), there it recognize my Forza 4 achievements but nothing from my Horizon 2 and F&F Version.
Anybody knows what is going on? or How to fix that???
Thanks Guys1!!
I tried to uninstall the HUB and install again… no luck!!! 
Look in the FM5 discussion forum and you will see several posts about the FM6 rewards. Lots of folks are saying that the F&F game in particular does not update stats. Mine updates the Gamerscore, but not any of the other 5 items in the Hub.
Turn 10 knows about it, based on the forum posts, and they will go back and make corrections. Right now they appear to be working on the new release! Just read through those posts and you will see that it’s happening to others as well. Hopefully they will get it updated soon for each of the games.
Even here I noticed that a few players are having this issue!
I don’t have Forza5 and I’m not buying right now because I’m waiting for the Forza 6!!! 
Let’s see until there if they gonna fix that!!!
I hope so.
Thanks my friend!