For starters, the weekly rewards that you get from the Forza Hub isn’t working properly for me in FH4, I’ve redeemed at least 5 rewards and they never showed up in the game, however, they work just fine in other titles.
Also, some of the game’s stats in Forza Hub has stopped updating anymore since I don’t really know when. I’m talking about the stats that are converted to scores which determine your level. I’ve driven more than 7000 miles in FH4 but the stats in the app remains at 1400. The same goes for days played, which remains at 5 days and car masteries completed, which is still 0. Strangely though, the gamerscore is updating normally.