This may be expected behavior, if so feel free to close.

We were trying to recursive copy files to maintain folder structure, but in one instance all of the files were under the same subfolder so the plugin didn't see it as a recursive copy.

Works fine

Matcher: **/*
dir1/subdir1/file1
dir1/subdir2/file2

Not viewed as recursive

Matcher: **/*
dir1/subdir1/file1
dir1/subdir1/file2

As a workaround, we added a useless file under dir1 which caused the plugin to view it as a recursive copy.