I went to Forza Horizon 3 Forum and found this Moderator that you can ask about your problem and he will investigate it. :
Ill be updating the release notes soon. However, I just wanted to mention that there were no game changes made. We only added an in game message if you have an issue syncing your profile from the cloud. This would not cause you to have any of the issues you are describing here. If you have an issue, and cannot find it here, you can email me firstname.lastname@example.org and I can start an investigation.
so I wrote so maybe it fixes and crap it on AMD only drivers