Many games including Fortnite and Call of Duty feature in game chat, which is best to use when playing cross platform. If you encounter an issue where either the other players can't be heard or the mic doesn't seem to be working, try this to make it work:
- Go into the game's audio setting and disable the chat feature.
- Quit the game and open it again.
- Now go back into the game's audio settings and re-enable the chat feature.
In most cases this will fix the issue and game chat will start working again.