FOTA from intermediate worked and now getting "Device not supported"

[robbsadler]

I ran this exercise a month or two ago and it worked to do OTA updates. I then tried recently again and it is giving me "Device not supported" in the Nordic Device manager app when I choose to do the update. 

I must be doing something different, but don't know what it could be. 

Here are the steps I took:

- Wiped out the folder where I was putting the ncs-inter git clone, and re-cloned it.

- Selected the l8_e3 exercise in the v2.6.2-v2.5.2 folder.

- Created a build config for my nrf52840dk using the nrf52840dk_nrf52840 board

- Modified the prj.conf file to include:

CONFIG_BOOTLOADER_MCUBOOT=y

CONFIG_NCS_SAMPLE_MCUMGR_BT_OTA_DFU=y

- Built and flashed the firmware to the board

- Added an extra printk() line to modify the file and create a visible change and build the project.

- copied the app_update.bin to my phone and attempted to do the update, and I get:

Greatly appreciate any clues on how to get this working. 

[robbsadler]

Environment info:

Using VSCode with NRF Connect on Windows, and I have both 2.6.1 and 2.8.0 toolkits installed.