EC21 modules reboot themself endlessly every 50 seconds

I have 3 EC21 modules that have been returned for repair that exhibit the same symptoms. They reboot themselves after about 50 seconds - but they do enumerate on USB.

I would like to try reflashing the firmware, current version is Revision: EC21EFAR06A01M4G

Where can I find the latest version ?

Please provide your email address and I will send you the new firmware version.thanks.

the Email has been sent.I hope it helps. Thank you.