I tried your code, and it appeared to work, returning

IP_MATCH is turned on Session loaded 209957231a595d0c638d37cda1f4d2a8

but I noticed that the session ID that is printed is not pulled from the loaded session object "$cse", it's pulled from the "$sessionid" variable which was set by the original session. With that in mind, I modified the coded a little. adding

print $cse->id;
[download]

to the end.

use strict;
use warnings;
use CGI;
use CGI::Session;

my $session = CGI::Session->new();
$session->expire('5m');
$session->param( 'TestName', 'TestValue' );
my $sessionid = $session->id;
$ENV{REMOTE_ADDR} = '127.0.0.1';
$session->flush;

$session = CGI::Session->new($sessionid);
CGI::Session->import qw/-ip_match/;
$CGI::Session::IP_MATCH = 1;
print "IP_MATCH is turned on\n";

if (my $cse = CGI::Session->load($sessionid)) {
     print "Session loaded\n";
}
else {    
     die CGI::Session->errstr();
}
print $sessionid, "\n";
print $cse->id;
[download]

The result:

500 - Internal server error.
There is a problem with the resource you are looking for, and it cannot be displayed.

So it's like the session is still not loading. If I change the code a little more.

use strict;
use warnings;
use CGI;
use CGI::Session;

my $session = CGI::Session->new();
$session->expire('5m');
$session->param( 'TestName', 'TestValue' );
my $sessionid = $session->id;
$ENV{REMOTE_ADDR} = '127.0.0.1';
$session->flush;

$session = CGI::Session->new($sessionid);
CGI::Session->import qw/-ip_match/;
$CGI::Session::IP_MATCH = 1;
print "IP_MATCH is turned on\n";

my $cse = CGI::Session->load($sessionid);

if ($cse) {
     print "Session loaded\n";
}
else {    
     die CGI::Session->errstr();
}
print $sessionid, " - \n";
print $cse->id, " - \n";
[download]

I get a returned Session object, but no session data. Notice I pulled defining the "$cse" variable out of the if statement.

result of the above code is:

IP_MATCH is turned on Session loaded 35d4f016b7aca2f7b3ae032291d2ec74 - -