I am using a Chinese GPS device, EV49

This is a 4G network device with the gt06 protocol. Recently, a problem was discovered. After the device was turned on and ignited, it was found that the ignition information was not present, but after the device turned off, the ignition information was present again, which caused the ignition and shutdown push to fail

That's pretty common for GT06 based devices. Ignition is only included in some messages.