On the source which was cloned can I assume you had performed the one-time login and setup of the login account? If this is the case, then the first boot on the unit restored to should not need first time boot content. Using the “-r” option (manually) in a flash.sh operation would not add that content back in, but some uses of the actual SDK Manager might.
When you clone you get both a “.img” and “.img.raw” file. What is the exact size of the “.img.raw” file, and is this the file you used (either one works, but I throw away the “.img” file and keep only the “.img.raw” since is the only one which can be edited or viewed)?
What was the exact “flash.sh” command you used to add the clone?
Are you sure the system hung, or is it just video failure? Can you still ping or ssh to the unit?