Tuning issues from offline to online

been noticing that when you are offline and tuning your car it handles the way you tune it but online it handles like you have done nothing to the car. this has never been an issue through forza till now, im starting to wonder if the new cloud based game isnt preforming like it should. one day my car will set good times and handle like i have tuned it other times it will be all over the track this usually happens after an update to the game, (but this does not affect all of my cars) anyone figure a way around this?