Azure IoT Hub some devices ignore FOTA
We have a few 100 devices connected to the IoT Hub, and connectivity and Device2Cloud messages runs flawlessly.
However, on some devices we experience FOTA problems, and also Cloud2Device messages are sometimes ignored/missed (on the device).
Mostly, FOTA and C2D messages runs fine, but some devices ignores FOTA, a few times or always (> 25 times).
We have no detailed log on device, as this is difficult to reproduce in a debug environment.
All devices are equal, running FW (on device) is the same.
Device runs Nordic Semiconductor's nRF9160, with nRF Connect Toolkit and SDK ver 2.0.2 (MCUBoot).
Plenty of free flash/ram on device.
We trig the FOTA via az command line (az iot hub device-twin update).
Diagnostics/Logs on the IoT Hub shows nothing (no errors).
Diagnostics/Logs on the IoT Hub is identical on devices that runs ok FOTA vs those failing/ignoring FOTA.
Any hint/comments on how to resolve this will be highly appreciated!