W5500 stop working at -40C

TCP/IP Chip W5500
1

Hello,
I have encountered an issue with the W5500 ethernet IC. During our environmental testing, we subjected our product to a temperature of -40°C for 4 hours. Afterward, we noticed that the W5500 is not functioning. The microcontroller that is operating W5500 show there is no W5500 IC.
W5500 IC stop working totally.
I have two questions regarding this situation:

  1. What could be the reason behind this problem occurring?
  2. Could you please provide guidance on how to resolve this issue?
2

Please share:

  • if W5500 does not work even after you increased the temperature to normal 25C;
  • what exact procedure you used to freeze the whole device, in particular temperature profile graph and humidity reading, if you had been opening the test chamber when there’s temperature < 0C;
  • the full BOM of the parts used on the board which were subjected to -40C - with manufacturer part numbers;
  • material PCB is made of;
  • general device photo and circuit diagram of the device.