Currently there are 3 ways to purchase a Dragon board, please refer picture below
As it can be seen only those that buy the AWS kit will have a preinstalled Debian. Such an installation may have a more recent kernel that the one we support.
For such cases, we recommend to flash the EMMC / SD card with an appropriate software/kernel version. In the link below all linaro releases can be found:
The version we currently support is the one highlighted in the picture below
Click into that version, it clearly states the Kernel version number. Below is an screenshot from 18.01.
Note: The version 19.01 also uses the same kernel version.