Thanks for the advice, your were on the right track. I was iterating over @plist in a foreach loop, as shown in the script example I posted above. There's definitely something funny going on with the $_ variable in that loop. I was able to get a workaround going, shown below, by replacing the foreach loop with a for loop. In my larger script, I simply index into @plist when necessary using $idx. 
use strict;
use IPC::Open3;

my @plist = ("ABC","DEF","GHI");

print "plist Before ccmexec:\n============\n",join("\n",@plist),"\n===
+=========\n\n";

my $ccmexecResult;
my $idx = 0;
for ($idx = 0; $idx <= $#plist;$idx++){
    $ccmexecResult = ccmexec_nodie("echo HelloWorld");
    
    print "ccmexec returned: $ccmexecResult\n";
    print "plist After ccmexec:\n============\n",join("\n",@plist),"\n
+============\n\n";
}

sub ccmexec_nodie {
    my $command = $_[0];
      
    my ($mystdin,$mystdout,$mystderr);
    my $pid = open3($mystdin,$mystdout,$mystderr,$command);
   
    my $myresult = "";
    while(<$mystdout>){
         $myresult = "$myresult$_";
    }
  
    return $myresult;
}

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In reply to Re^2: Why are elements of my array getting deleted? by iKnowNothing
in thread Why are elements of my array getting deleted? by iKnowNothing

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