Hello Daniel,
I think that debugger module was released with Kamailio version 3.1.0. wasn't it?
As I'm running Kamailio 3.0.0, I have set up debug=9.
Here you have my config file, the raw capture of the call and the lines in kamailio log file.
I see some messages regarding cpl-c module, and I was experiencing some problems with it too. I tested without cpl-c module and I get the same trace but no messages in log file.
Thanks in advance.