I had this problem after nearly 3 years of use, Things that didn’t work for me: - Restarting the phone. - Resetting the phone. - Using *#*#4636#*#* menu to change to other sim card settings. - Changing the sim-card. - Sending phone to repair to check if there is any hardware related problem. In the end, I end up buying a new phone. Such a shame a perfectly good phone had this problem after less then 3 years of perfectly good use. Please let me know if you figured out a way to make the compact x work again.