Hey hquaadhhw7im,
Just to confirm, are you trying to play Command & Conquer: Rivals?
If so, please try the following troubleshooting steps:
- Check whether your iPhone is up to date
- Close all apps that are open in App Switcher
- Delete the app, restart your device, and reinstall it
- Check if you have at least 5Gb of storage left on your device
- Try opening the game on mobile data
- Disable 'Game mode'
- Under Settings, find the game and ensure Local Network and Background App Refresh are on
- Go through these iPhone troubleshooting steps
Let us know how it goes, thanks!