flash for iphone 8 plus

Good afternoon. I have such a problem. During night photography at an air temperature of -5C degrees, the flash works in the floor of incandescence. only one of the four LEDs blinks. photos are not obtained. although if you immediately turn on the flashlight from the control point, all the LEDs are bright and normal. This indicates that the hardware is working fine. It's most likely the software. I ask you to understand this. now I'm taking pictures so - turn on the flashlight for a few seconds, then turn on the camera application and the flash works one or two photos. I have an iphone 8 plus ios 11.1.1.