thermo_modify - lost error/warn/ignore keyword

Hi everybody,

my problem is the following: if I set the value of 'thermo_modify lost value' to error or warn, I do not get an error or warning message during the execution of the simulation although particles are leaving the simulation domain.

More details:
I am working on some tutorials in LIGGGHTS and tried to modify geometries and the input script a little bit. My current problem is similar to the conveyor tutorial, but at the end of the conveyor, there is a "hole" at the bottom of the box (no granular wall) and the particles are leaving the simulation domain (on purpose). I can recognize this during the postprocessing and also on the screen output (number of atoms is decreasing).
I wanted to try the functionaly of the 'thermo_modify lost value' command, but no error or warning message is shown. So my question is if somebody else had the same problem or if I misunderstand the purpose of this command.
I have also tried to modify the binflow tutorial of C. Stoltz with this command (to receive an error or warning message), but there it is also not working out as I would expect it.

Best regards
Harald