To add a friend on the TCL MOVETIME Family Watch MT40X, shaking the watches is not the recommended procedure. Here are the correct steps to add a friend or family member:

- You need to use the TCL Connect app on your smartphone.
- In the app, you can choose to share a QR code. A QR code will appear on the watch screen.
- The guest must scan this QR code using the TCL Connect app on their own smartphone.

The difference in model (44mm vs 42mm) should not be a problem for this feature, as the procedure for adding a friend depends on the app and not the size of the watch. Make sure that both watches are correctly configured and connected to the TCL Connect app.

It's about adding a friend with the watch and not someone who has a smartphone so no app.
My daughter had the 42x before and the method of shaking the watches to add friends for messages worked....