An err with cli not starting

Device:

RasberryPi 3b+
OS version 8.2
SD card 64GB

Problem:

system is running fine but just broken while i am out side.i don’t know how it’s happend,i’ve tried search on github for this problem but got no fixed, while i input “login” in the cmd line,it doesn’t working, just reflash the screen and show the problem again,It’s the netwokring err? or something else… idk. it’s any one got the same thing?,help plz~