To troubleshoot the issue of the NuMi app not opening on your Pixel phone, follow these steps:

1. Restart the Phone: Begin by restarting your Pixel phone. This simple step can often solve many app-related issues.

2. Clear Cache and Data:
- Go to Settings on your Pixel phone.
- Scroll down and select Apps & notifications.
- Tap on See all apps and find NuMi.
- Select Storage & cache.
- Tap on Clear Cache and then Clear Storage/Data. Note that clearing storage will reset the app to its original state.

3. Check for App Updates:
- Open the Google Play Store.
- Tap on your profile icon in the top right corner.
- Select Manage apps & device.
- Check if there's an update available for the NuMi app. If there is, install it and see if the app opens.

4. Reinstall the App:
- Uninstall the NuMi app by going to Settings > Apps & notifications > NuMi > Uninstall.
- After uninstalling, reinstall the app from the Google Play Store.

5. Safe Mode: If the issue persists, you can boot your phone into Safe Mode to see if any third-party app is causing conflict:
- Press and hold the power button until the power off icon appears.
- Press and hold the Power off option until you’re prompted to reboot to Safe Mode.
- Tap OK to confirm. In Safe Mode, only the pre-installed apps will run.
- Try opening the NuMi app in this mode. If it works, the issue may be caused by one of your third-party apps.

6. Check for System Updates:
- Go to Settings > System > System update.
- If there is an update available, download and install it.

7. Factory Reset (Last Resort): If none of the above solutions work, consider performing a factory reset as a last resort. This will erase all data on your phone, so be sure to back up your important information:
- Go to Settings > System > Reset options > Erase all data (factory reset).
- Follow the prompts to reset your phone.

After trying each step, test the NuMi app to see if the problem has been resolved.

If you require further information on how to fix apps on Pixel devices, you can refer to this helpful guide - [learn more].