You should connect to the rsh daemon with strace and look for setrlimit calls:
strace -p $PID -f -e trace=setrlimit
They should differ in both versions. This should lead you to the problem.
Why ulimit shows different outputs? [closed]
You should connect to the rsh daemon with strace and look for setrlimit calls:
strace -p $PID -f -e trace=setrlimit
They should differ in both versions. This should lead you to the problem.