hello i had this issue aswell, i was working on this on my free time and i reach to this part of code,  i would like to share what i found 

https://github.com/jenkinsci/kubernetes-plugin/blob/master/src/main/java/org/csanchez/jenkins/plugins/kubernetes/KubernetesProvisioningLimits.java#L91

there is a option called podTemplate.getInstanceCap() that theorically can be set and can posible stop the massive pod creation , if not set  by default is set to Integer.MAX_VALUE which is very big value, i have not found the way to set this value yet on the pod template but i will report if i find anything new

https://github.com/jenkinsci/kubernetes-plugin/blob/master/src/main/java/org/csanchez/jenkins/plugins/kubernetes/PodTemplate.java#L328

i think i found the way while i was doing some experiment, try to following , add  instanceCap: 1 to your pod template definition, in my laboratory is accepting the parameter , let me know if is working for you  

podTemplate(inheritFrom: "<yourpodtemplate>", showRawYaml: false, instanceCap: 1){}

Thanks for the quick response.  I added the instanceCap like the following:

podTemplate(
    instanceCap: 2,

...

Then simulated the issue by deleting the  jnlp container of the pod, and jenkins still keeps recreating the pod none stop.  I got the same result with instanceCap: 1.

The simulation is on the only available worker node of the k8s cluster, run the following:

while true; do echo $SECONDS; sudo crictl ps --name jnlp -q|xargs -r sudo crictl rm -f ; sleep 1; done

hello good morning, i just wake up, let me check what can be the cause of the difference and i will get back at you if i found anything useful  to share 

i have erased the instancecap and my instance creation are stopped after a while so i beleive something else in my laboratory is stopping the massive pod creation ,  i saw that we have a admission controller called eventratelimit with a configuration for namespace, i beleive that is the one that is actually stopping the pod creation and not the plugin by itself 

https://github.com/kubernetes/kubernetes/blob/v1.24.0/plugin/pkg/admission/eventratelimit/apis/eventratelimit/types.go#L54

anyways , let focus on the plugin, the problem itself is that when the pod terminate it disconect from jenkins (which cause a unregister in here https://github.com/jenkinsci/kubernetes-plugin/blob/master/src/main/java/org/csanchez/jenkins/plugins/kubernetes/KubernetesProvisioningLimits.java#L107 decreasing the value again to 0 instance running ) ,i tried to see if  pod retention allow the failure pod stay connected to jenkins so its count as a running instance and allow us to reach the instancecount but that only let the pod stays in kubernetes, pod still get disconected from jenkins at all cost due to this part (the disconection of jenkins slave jnlp from jenkins master also cause a unregister )

https://github.com/jenkinsci/kubernetes-plugin/blob/master/src/main/java/org/csanchez/jenkins/plugins/kubernetes/KubernetesSlave.java#L322 ,  at this point , the only solution that comes in mind will be to adjust the code to add  a counter that count the time that a pod fails and compare before the next pod creation , just in the part of this  code https://github.com/jenkinsci/kubernetes-plugin/blob/master/src/main/java/org/csanchez/jenkins/plugins/kubernetes/KubernetesLauncher.java#L94

the other solution will be on kubernetes and should be an customizable  admission controller but that is unknow territorry  for me