We should check the console output of the LS.bat script when launched as a service.
I'm not sure if Windows or nssm allow you to do it in some way.
Anyway, you can try to setup a wrapper script that runs LS.bat and redirects the output.
For instance, create wrapper.bat beside LS.bat, which issues
.\LS.bat run > out.txt
and change Install_LS_as_Service-NT.bat by replacing references to LS.bat with wrapper.bat;
then let's see the out.txt log generated.