Thanks

This behaviour corresponds exactly to what I experience in my further reduced script:

use v5.30.0;

'ABC' =~ /B/ if @ARGV;

my $last;
say ' (\'NAME\'=~/$last/i)=', 'NAME' =~ /$last/i ? 1 : 0;
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Output when called without arguments:

D:\>surprise.pl
 ('NAME'=~/$last/i)=1
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Output when called with arguments:

D:\>surprise.pl all
 ('NAME'=~/$last/i)=0
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