Hi there! I understand you're having issues with the Vanguard app where about half the features you need aren't working. That sounds inconvenient. Could you tell me a bit more about which specific features are not working for you? Also, have you noticed this issue started recently or after any updates?

In the meantime, let's start with some basic steps to help get things running smoothly on your iPhone with iOS 18.6:

1. Check for App Updates: Make sure you have the latest version of the Vanguard app installed. Developers often release updates to fix bugs and improve features.

2. Restart Your Device: Sometimes a simple restart can refresh the app’s performance.

3. Check Your Internet Connection: Ensure you have a stable internet connection, either Wi-Fi or cellular data.

4. Clear App Cache (if possible): iOS apps don't have a direct cache clear option like Android, but you can try deleting the app and reinstalling it. This often clears any corrupted temporary files impacting functionality.

5. Verify Your iOS is Updated: You mentioned you’re on iOS 18.6, which is recent, so that's good.

If these do not resolve the issue, there might be a backend or app-specific problem, possibly known or being worked on. I can look into any ongoing Vanguard app issues for your region or similar reports.

Does anything particular stand out when you try to use the app? For example, do certain screens freeze, buttons not respond, or features not display? This info will help me troubleshoot further!