We've noticed that for certain smartphones, the watchdog is triggering while in dfu mode.
We're using nRF5_SDK_15.2.0.
Thanks for your support!
The WDT should be fed in the bootloader project (unless you removed it).
What is the timeout value of the WDT?
Can you try to use the debug version of the bootloader (pca10056_ble_debug) and check the logging from the WDT?
You must enable logging and enable logging for the WDT in sdk_config.h.
#define NRF_LOG_ENABLED 1#define WDT_CONFIG_LOG_ENABLED 1