you probably have two perls installed, so fix your shebang

so however you ran cpan , run it again, then see which perl is running with

cpan[1]> !print $^X,$/;
C:\perl\bin\perl.exe
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You can compare to whichever cpan you're running  head -n2 `which cpan`

Or run  which perl and run perl yourfile which will always use the current perl (first perl in $PATH ), which should be the same as the perl of first cpan in path