Hi there! I understand that your Mega Millions & Powerball app on your iPhone running iOS 18.6 is not saving your numbers. Let's get this sorted out together.

To help me assist you better, could you let me know:
- Are you trying to save favorite numbers, or numbers for a ticket purchase?
- What exactly happens when you try to save the numbers? Any error messages or does it just not store them?
- Have you recently updated the app or iOS version?

Meanwhile, here are some straightforward steps you can try to fix the issue:

1. Restart the App
Close the Mega Millions & Powerball app completely (swipe it away from the app switcher), then reopen it and try saving your numbers again.

2. Check for App Updates
Go to the App Store, check if there’s an update available for the Mega Millions & Powerball app, and install it. Updates often resolve bugs.

3. Ensure App Permissions
Sometimes storage or permission settings interfere. Go to your iPhone Settings > Mega Millions & Powerball app and make sure it has permission to store data and access necessary features.

4. Clear App Cache or Data (if available)
While iOS doesn't allow clearing app cache directly, if the app has an option in its settings to clear saved data or reset, try that. Otherwise, proceed.

5. Reinstall the App
Delete the app and reinstall it from the App Store. After reinstalling, log in if required and see if it saves your numbers now.

If these steps don’t fix the problem, we may need to check if this is a known issue with the app or if there’s any server-side problem.

Could you please tell me which steps you’ve tried already? That way, I can suggest more advanced options if necessary.