Hi! I understand you're having trouble adjusting the slider controls and changing program settings in the Hearing Remote app on your iPhone. To help you better, could you please tell me if the app recognizes your hearing aids properly? Also, are you seeing the sliders but just can't move them, or are they unresponsive or grayed out?

Meanwhile, here are some initial steps you can try:

1. Confirm Connection: Make sure your hearing aids are switched on and connected via Bluetooth to your iPhone. You can check this in your iPhone's Bluetooth settings.

2. Close and Reopen the App: Sometimes, restarting the app helps. Swipe up from the bottom of the screen (or double-click the Home button if your iPhone has one) and swipe the Hearing Remote app off the screen to close it. Then open it again.

3. Update the App and iOS: Make sure both your iPhone iOS (which you've mentioned as 18.5, so likely up to date) and the Hearing Remote app are at their latest versions.

4. Check App Permissions: Go to iPhone Settings > Hearing Remote and confirm it has the necessary permissions. Sometimes lacking Bluetooth or microphone access can affect controls.

5. Adjust from Devices Tab: According to the Hearing Remote User Guide, the device settings and sliders are available under the "Devices" tab inside the app. Have you tried accessing your hearing aids there to adjust settings?

If you've done these or still face the issue, please let me know what steps you've already tried, and if possible, the model of your hearing aids. That way, I can guide you through more specific or advanced troubleshooting.