Flashing Custom Yocto Image

Hi,

I am trying to add IPSec to the WP7702 on the magOH Red.

To achieve this I downloaded the tarbal and

Added the following to local.conf
DISTRO_FEATURES_append = " ipsec"

And created a custom recipe file similar to mdm9x28-image-minimal with the addition of
IMAGE_INSTALL_append = "
strongswan
"

I then successfully built the image

I downloaded the modem firmware and legato firmware from the source site

I created a custom spk using:
swicwe -o custom-firmware.spk -c SWI9X06Y_02.22.12.00_00_SIERRA_001.021_000.spk yocto_wp77xx.4k.cwe legato-18.09.2.cwe

Flashed it using:
swiflash -m WP77XX -i custom-firmware.spk

I got:
Firmware Download SUCCESS

However it seems that the image on the device does not contain the updated firmware, I was wondering if I am doing something wrong along the way.

Thanks,
S