I know this is a “how to get started”, but it might be worth adding when building the Yocto for Mender, you should also put in a unique release name. Otherwise, you’ll get multiple .mender files that that show up as the template text of “release-1” as you do more builds.
Here is what I did in my setup, I use what I’m building plus the date and time.
# The name of the disk image and Artifact that will be built.
# This is what the device will report that it is running, and different updates
# must have different names because Mender will skip installation of an Artifact
# if it is already installed.
MENDER_ARTIFACT_NAME = "rpi3-20220512-1956"