Does not parse Perl files with no extension?

[jaguart]

Newbie, so apologies if I've missed something. Environment: Windows 11 VSCode client, Debian WSL server - all appears to be working fine.

Our Perl scripts do NOT have a .pl extension.

I have "perl.fileFilter": [""] in settings.json

I see LS: initial parsing done, loaded 44 files, parsed files, 44 files and wonder about the number of parsed files being blank?

This screenshot shows a tiny script, the LS output and an empty Outline - I would have expected to see the sub foo in the Outline:

So I think the LS has an issue with files without an extn?