SIM card is inserted. Device has been restarted and even reset

Then the clock is still registered with the predecessor in the tcl app you have to get in touch with the predecessor he has to delete it from the tcl app also had the problem

Katastrophe!

The unit may have belonged to a previous owner. We bought a watch here that was marked as used and fully functional. Insert the SIM card, then the watch suddenly appeared as already paired. Another father even appears under Contacts. The watch is unusable. You can't pair the watch again because the previous owner is still connected to the watch. Absolute disaster!

Go onto Google Play store, and have a read of the TCL Connect reviews. Most are 1-star reviews, mostly complaining about how the IMEI Is not recognised by TCL's own app. This problem has been going on for 3 years, and yes, we're having the same issue. Their technical support has not replied to my email. This is a RUBBISH watch though... I'm ready to put it in the bin !

Had the same problem and now solved. Only TCL support can unpair it from the predecessor. There is a swiss support line.

I bought the Movetime Family Watch MT40 with SIM card from Digitec and was able to set it up without any problems.
Please note the following if pairing via QR is not possible;
1. SIM card registered if from Digitec, otherwise go to iot.digitec.ch to register it.
2. SIM card inserted correctly
3. switch on the clock.
4. is signal 3G or E displayed on MT40 top left ?
If no network operator is displayed, pairing to the app on your smartphone is not possible.