Hi there! I see your Lingo app's Bluetooth hasn't connected since 10 PM, even after turning it off and restarting your phone. I want to help you get this sorted out.

To start, could you please tell me:
- Are you using the Lingo app with a specific Bluetooth biosensor device?
- Have you tried toggling Bluetooth back on after the restart?
- Is your phone kept within about 33 feet (10 meters) of the device?
- Are you running the latest version of the Lingo app from the App Store?

This info will help me guide you better. Meanwhile, here’s a step-by-step basic troubleshooting approach we can start with:

1. Ensure Bluetooth is On: Go to your Mac's System Preferences > Bluetooth and make sure it’s turned on.
2. Restart Bluetooth: Turn Bluetooth off, wait about 10 seconds, then turn it back on.
3. Close and Reopen the Lingo App: Sometimes the app needs a fresh start to reconnect.
4. Check Proximity: Keep your Mac and the biosensor device close during pairing.
5. Forget and Re-Pair Device: If your Mac has the biosensor saved in Bluetooth devices, remove it, then attempt to pair again through the Lingo app.
6. Update the App and macOS: Make sure the Lingo app and macOS Catalina (10.15.7) are up to date to avoid compatibility issues.

If these steps don’t resolve the problem, there might be a pairing error, or the sensor might require re-pairing using NFC by placing the top edge of your phone or device near the sensor to trigger pairing again.

Please let me know what you've tried already or if anything specific happens when you try to connect, like error messages or signals. That way, I can adjust guidance accordingly!

Are you ready to try these steps, or do you have more details for me to help?