That's a long known issue which can only be solved by patching cperl-mode.

I identified the necessary changes in a discussion in "gnu emacs help" some years ago and Ilya welcomed any patches...¹

Don't know if recent versions already solved this...

HTH ! =)

Cheers Rolf

( addicted to the Perl Programming Language)

update

An easy workaround is to put the opening bracket into the next line...

Sorry can't demonstrate while on mobile...

update

See also http://www.emacswiki.org/emacs/IndentingPerl

footnotes
¹) see here CPerl-Mode Indentation and here

In reply to Re: Formatting Perl code with Emacs (updated) by LanX
in thread Formatting Perl code with Emacs by isntvoid

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