Example "MC20_GPRSHTTP" does not work on Wio Tracker

When I run the other example “MC20_SMSSend”, the registration of network fails (the code is: gpsTracker.waitForNetworkRegister()). There is one interesting thing: when I installed the 4G sim card of China Telecom, the “NET” led on the board blinks. It does not blink with CMCC sim card.