Hi there! I understand you're seeing "watchxphone" on the screen and the AI feature in the Letsfit app isn’t working on your iPhone with iOS 18.5. Let’s see if I can help you get this sorted out.

To start, could you tell me a bit more about when exactly this "watchxphone" message appears? For example, does it show up when you try to connect your watch to your phone, or when you launch the AI feature? Also, have you already tried any fixes like restarting the app or your devices?

Based on what you're describing, it sounds like your Letsfit watch might not be properly connected to your iPhone, which would prevent the AI features from working. Here’s a step-by-step approach to troubleshoot this:

1. Check Bluetooth Connection:
- Make sure Bluetooth is enabled on your iPhone. You can do this by opening the Control Center and ensuring the Bluetooth icon is blue.
- Go to your iPhone’s Settings > Bluetooth and see if your Letsfit watch appears as "Connected." If not, try tapping it to reconnect.

2. Restart Devices:
- Restart your iPhone by turning it off and on again.
- Power off your Letsfit watch and turn it back on.

3. Reopen Letsfit App:
- Close the Letsfit app completely by swiping it away in the app switcher.
- Launch the app again and try to connect.

4. Check for App and Firmware Updates:
- Open the App Store and check if there’s an update for the Letsfit app.
- In the Letsfit app, look for any firmware update notifications for your watch and install if available.

5. Re-pair the Watch:
- If the above steps don’t work, try unpairing your watch.
- In the Letsfit app, go to device settings and remove or unpair the watch.
- Then follow pairing steps again to set it up fresh.

If after trying all these you still see the "watchxphone" screen and the AI isn't working, please let me know what step you reached and any error messages you see. I’m here to help you get this back on track!

Are you okay to start with these steps?