Forza Horizon 4 allows cross-play between 2 platforms

Supported crossplay platforms
Release Date: Oct 2, 2018
Official Website: Link
Summary:
Live the Horizon Life when you play Forza Horizon 4. Experience a shared world with dynamic seasons. Explore beautiful scenery, collect over 450 cars and become a Horizon Superstar in historic Britain.
Genres and Themes: Racing Sandbox
Supported crossplay platforms:
Forza Horizon 4 is supporting cross-play across multiple platforms. Currently it is possible to play together with your friends on Windows PC and XBox One.
Supported game modes:
  • Single player
  • Multiplayer
Supported player perspectives:
  • First person
  • Third person