Behaves differently to asciidoctor command when converting a directory

[AlexCzar]

Ruby variant of asciidoctor produces output directory that is a mirror of src directory with adoc files converted to html
; asciidoctor -R srcdir -D targetdir srcdir/'**/*.adoc'
Whereas asciidoctorj variant:
; asciidoctorj -R srcdir -D targetdir srcdir/'**/*.adoc'
produces flat output directory containing all html files at root level.

Ruby asciidoctor's approach is of course preferred.

Environment

; asciidoctor --version 
Asciidoctor 2.0.18 [https://asciidoctor.org]
Runtime Environment (ruby 3.1.3p185 (2022-11-24 revision 1a6b16756e) [x86_64-linux-gnu]) (lc:UTF-8 fs:UTF-8 in:UTF-8 ex:UTF-8)

; asciidoctorj --version 2>/dev/null
AsciidoctorJ 2.5.7 (Asciidoctor 2.0.18) [https://asciidoctor.org]
Runtime Environment: jruby 9.3.8.0 (2.6.8)