"ulimit -c unlimited" fails when done "sudo user -c shell-some-script"

I have on a Linux server with SuSE Linux Enterprise 15 SP5 the following situation:

I have two unpriv users "sisis" and "jenkins" which are both allowed (based on entries in /etc/security/limits.conf) to run the shell build-in command "ulimit -c unlimited":

linux:~ # su - jenkins jenkins@linux:~> id uid=1003(jenkins) gid=100(users) Gruppen=100(users) jenkins@linux:~> ulimit -c unlimited ; echo $? 0 exit linux:~ # su - sisis sisis@linux:~> id uid=900118(sisis) gid=900118(sisis) Gruppen=900118(sisis),403(userdevl) sisis@linux:~> ulimit -c unlimited ; echo $? 0 exit 

But, when the user "jenkins" wants to do this in a shell script as user "sisis", this gives an error:

linux:~ # su - jenkins jenkins@linux:~> cat /tmp/ulimit.sh #!/bin/sh export LANG=C ulimit -c unlimited jenkins@linux:~> sudo -u sisis -g sisis /tmp/ulimit.sh /tmp/ulimit.sh: line 3: ulimit: core file size: cannot modify limit: Operation not permitted 

The background of this silly question is, that for test automation from another server (a Jenkins Continuous Integration server) jobs are started remotely as

ssh jenkins@linux bash CATserver_start.sh + sudo -u sisis /opt/lib/sisis/catserver/etc/S99catserver.testdb start 

i.e. the "ulimit -c unlimited" command is issued in the above shellscript /opt/lib/sisis/catserver/etc/S99catserver.testdb which in production is started as user "sisis", but in test automation from the Jenkins CI server via SSH as user "jenkins".

Any ideas?

Additional information to answer the question in the comment:

The real command is as given:

ssh jenkins@linux bash CATserver_start.sh + sudo -u sisis /opt/lib/sisis/catserver/etc/S99catserver.testdb start 

The exmples given with the script /tmp/ulimit.sh was only to simplfy the problem. The script /opt/lib/sisis/catserver/etc/S99catserver.testdb uses as she-bang #!/bin/bash and after su - sisis the user uses also a bash:

linux:~ # su - sisis sisis@linux:~> ps PID TTY TIME CMD 21146 pts/1 00:00:00 bash sisis@linux:~> ulimit -a core file size (blocks, -c) unlimited data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 14448 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 65535 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 65535 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited