The specific version number you mentioned, v1.671.650 , corresponds to a recent update for Forza Horizon 5
Stay safe, keep racing, and enjoy Mexico the way it was meant to be played — legitimately. forzahorizon5updatev1671650runepart1 link
Yeah. Did you get this update?
Playground Games releases updates roughly every 4–6 weeks. These include: The specific version number you mentioned, v1