I had to run the script from the root using .desktop
Symptoms: when you start asking for the password and exits.
File .desktop standard, $path prescribed
The variable Exec=pkexec env display=$display xauthority=$xauthority myscript
The script is valid.
Logs the script does not write to his performance, it seems, never comes.
When you try enforcing "pkexec env display=$display xauthority=$xauthority /full/path/myscript" in the console works normally.
Supplement $Exec full path doesn't work - the symptom was repeated.