This could be caused by various things, but one of the most common reasons that you might not see your globbing pattern recurse all folders is due to a bash configuration option. The relevant option is called globstar. Sometimes globstar will be turned off by default and it needs to be turned on. If you'd like the recursive glob pattern ** to recurse subfolders then globstar should be turned on.
If you're using bash v4 or higher you can turn it on with
shopt -s globstar. Please note that this will have to be set at the start of every step, as each step runs in a separate subshell.
If you would not like this glob pattern to recurse across folders, turn this option off with
shopt -u globstar.