Lost tunes!!

Hey I’ve been playing forza since forza 1 and never had an issue so annoying, seems every time I come back on the game random cars I have spent hours tuning are randomly reverted back to stock form? Has anyone had this issue? Add this to your list turn 10!! While your at it fix the livery stuff In mp races, my friend always is able to see my livery but he is the painter so me not seeing his sucks as he puts Lot of time into them please reply to this