Hi Martin,
it's working as designed
🙂
You've uploaded the software and left it on the default directory setting which is TFTP with the default directory of /tftpboot/firmware/images/
But the controller is set to SCP with the default directory of /root/firmware/images/
That's the reason you don't see a file in the assign image window.
Delete the file and upload it again but choose SCP.
-Ron