COUNTER_STATE_VAR is constant defined this way:

use constant {

  # ...

  COUNTER_STATE_VAR       =>      "%counter",

  # ...

};
[download]

Unfortunately, I am unable to reproduce with shorter example. I tried, but the output is consistent, when I am "snippetting" it out of its authentic context. I also cannot provide whole code base, because it contains a lot of information, which cannot be disclosed to third parties. Therefore I am seeking for tips, but the resolution is on me.