You need the Perl's version of rename. Seems like you use rename.ui:
If you run:
and you have:
$ file $-- "$(type -p rename)"
...ELF 64-bit
you have rename.ui.
If you have:
$ file $-- "$(type -p rename)"
.../rename: Perl script text executable
it's Perl's rename.
Check in depth explanations about Perl's rename:
Download or copy paste standalone rename