Problem with Jenkins images

little bit of a newbie so am very confused. can not seem to be able to modify an image.

STEP 1 : I get a docker image just fine and confirm it works

#docker run --user root -it jenkins/jenkins (i see jenkins starting)
Running from: /usr/share/jenkins/jenkins.war
webroot: EnvVars.masterEnvVars.get(“JENKINS_HOME”)
2022-12-02 01:17:49.043+0000 [id=1] INFO winstone.Logger#logInternal: Beginning extraction from war file
2022-12-02 01:17:50.634+0000 [id=1] WARNING o.e.j.s.handler.ContextHandler#setContextPath: Empty contextPath

docker run --user root -it jenkins/jenkins /bin/bash (get shell just fine)

root@0ed3e03csdr8:/#

STEP 2 : i make totally minor changes to the image (added a user, installed tree) only for testing purposes

STEP 3 : I commit the changes just fine & create a LOCAL image

docker commit -m “JenkinsMaster20221201” 0602630a8f77 jenkinsmaster20221201:abc

docker images

REPOSITORY TAG IMAGE ID CREATED SIZE
jenkinsmaster20221201 abc 835ss53f34f3 20 minutes ago 489MB

STEP 4 : I try to run my image

docker run --user root -it jenkinsmaster20221201:jsl /bin/bash

#root@4438ed60948a:/# (again just shell just fine AND i see my changes)

However,

docker run --user root -it jenkinsmaster20221201:jsl

root@4438ed60948a:/# (gives me back the shell only and does not start jenkins)

what happened? original image contains “something” that is firing up jenkins,
so may not be a docker issue, but wanted to verify in case i was doing something silly.