on your watchface, here's what you need to check:

Are your devices connected to Bluetooth?
To reconnect your watch and phone to Bluetooth, please:

Disable and enable Bluetooth on your phone and open the Wear OS by Google™ app.
On your watch, swipe up on your watchface and tap on the Settings icon .
Then, tap on Connectivity and select Bluetooth.
Disable and enable Bluetooth. You can check the connection status on your both your devices.

If you’ve tried this and your watch and phone still aren’t connecting, there are further checks you can perform:

Is your watch on Airplane mode?
Here's how to check if your devices are on Airplane mode:

On your phone, go to Settings and look for the Airplane mode icon.
On your watch, swipe down on the watchface and look for the Airplane mode icon . If it’s on, tap the icon to turn it off.

When Airplane mode is activated, the icon will be brighter, and the line will disappear . When the Airplane mode is off, the icon is crossed-out by a line

.

Restart your watch and phone
If you’ve made the checks above and your phone and watch still aren’t connecting to Bluetooth, restarting your watch and your phone may fix the problem.

To restart your watch:

Swipe down on the watchface and tap on the Settings icon
Tap System
Tap Restart

As a last option, you can try resetting your watch. Please keep in mind that resetting your watch will restore it to factory settings and delete all data.

To reset your watch:

Swipe down on the watch face and tap on the Settings icon
Tap on System
Tap on Disconnect & reset

Once you've reset your watch, go to the Bluetooth settings on your phone and select the option to forget the device. Then pair your watch with your phone again https://faq.tagheuer.com/articles/en_US/FAQ/How-do-I-pair-the-TAG-Heuer-Connected-with-my-phone

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