I am trying to flash all three images together. I have the firmware updating working, but if you flash them together, the bootloader doesn't know that the application is programmed. I found this post POST
There are differences however. I found the nrf_dfu_settings.c file, and found a similar line to what is referenced in the post. In nrf_dfu_types.h, I found defines that are similar, and I edited the line to add "NRF_DFU_BANK_VALID_APP" to the bootloader settings. This did not work however.
Are there other settings I need to change?