In this case it's definitely the (CAT)7, as if the pattern can be broken down into identical parts then it is treated as a smaller microsatellite. I have some code to do that, e.g.
my $v1 = substr($match, 0, 1);
my $v2 = substr($match, 1, 1);
next if ($match =~ /^($v1$v2){2,}$/);