Firstly, make sure that the USB interface (PC or other power supply) is powered properly.
Check if the USB connector is plugged in backwards.
Whether there is any dirt or corrosion on the charging port. Make sure the USB connector is securely connected to the power adapter.
When the power of the device is extremely low, it takes about 2 minutes to display the charging status or response.
Note: do not use high power chargers. fast chargers/power banks to charge the smartwatch.