The refresh rate for every game is set to "As system" by default.
Please follow the steps below to change the refresh rate manually for each of the games in your device:
1. Launch Armoury Crate from the bottom of Home screen.
2. Select the game you want to change in Games Lobby then tap Game Profiles.
3. Select Display from the options on left screen
4. Uncheck As system.
5. Select the refresh rate you want for the game and tap Save.
You can set different refresh rates for each game in your device.