The received text message shows that there are letters in front of the mobile phone number.

Reason: First, it may be that others sent pictograms composed of numbers and letters. Because of the different mobile phones, the space symbol has changed, the picture is distorted, and the numbers and letters you see are chaotic. Second, it may be that someone else's mobile phone system has a default picture sent to you, but your mobile phone does not have this default picture, so the code cannot be read and translated. Third, it may be that others deliberately spoof.