Agent is created via the "Amazon EC2 Plugin".
After the agent is up and running, navigate to the node in Jenkins UI:
https://XXX/computer/YYY/configure
And enter a new "Description". Save.

UI shows the "Opps. A problem occurred while processing the request" error.
Note, in the JSON that is being sent, the "Uptime" parameter key is an empty string. i.e. this bit taken from the full log below:

  "ec2Type": "On Demand",
  "": [
    "3 days 0 hr",
    "0"
  ],
  "publicDNS": "ZZZ.us-west-2.compute.amazonaws.com",

Full log is attached (too long).  Here is the first bit...

2024-08-19 13:46:04.831+0000 [id=645501]        WARNING o.e.j.s.h.ContextHandler$Context#log: Error while serving https://XXX/computer/YYY/configSubmit
org.kohsuke.stapler.NoStaplerConstructorException: There's no @DataBoundConstructor on any constructor of class java.lang.Boolean
        at org.kohsuke.stapler.ClassDescriptor.loadConstructorParamNames(ClassDescriptor.java:291)
        at org.kohsuke.stapler.RequestImpl.instantiate(RequestImpl.java:950)
        at org.kohsuke.stapler.RequestImpl$TypePair.convertJSON(RequestImpl.java:841)
Caused: java.lang.IllegalArgumentException: Failed to instantiate class java.lang.Boolean from {"metadataEndpointEnabled":true,"metadataTokensRequired":true,"metadataHopsLimit":"3"}
        at org.kohsuke.stapler.RequestImpl$TypePair.convertJSON(RequestImpl.java:845)
        at org.kohsuke.stapler.RequestImpl.bindJSON(RequestImpl.java:604)
        at org.kohsuke.stapler.RequestImpl.instantiate(RequestImpl.java:963)
Caused: java.lang.IllegalArgumentException: Failed to convert the metadataSupported parameter of the constructor public hudson.plugins.ec2.EC2OndemandSlave(java.lang.String,java.lang.String,java.lang.String,java.lang.String,int,java.lang.String,hudson.model.Node$Mode,java.lang.String,java.lang.String,java.util.List,java.lang.String,java.lang.String,java.lang.String,boolean,java.lang.String,java.lang.String,java.lang.String,java.util.List,java.lang.String,int,hudson.plugins.ec2.AMITypeData,hudson.plugins.ec2.ConnectionStrategy,int,hudson.plugins.ec2.Tenancy,java.lang.Boolean,java.lang.Boolean,java.lang.Integer,java.lang.Boolean) throws hudson.model.Descriptor$FormException,java.io.IOException
        at org.kohsuke.stapler.RequestImpl.instantiate(RequestImpl.java:965)
        at org.kohsuke.stapler.RequestImpl$TypePair.convertJSON(RequestImpl.java:841)
Caused: java.lang.IllegalArgumentException: Failed to instantiate class hudson.plugins.ec2.EC2OndemandSlave from {"name":"EC2 (vdm.qa.auto-node-static) - vdm.qa.auto-node-static (i-00ae1b2c81dbc5637)","spotInstanceRequestId":"","cloudName":"vdm.qa.auto-node-static","templateDescription":"vdm.qa.auto-node-static","instanceId":"i-00ae1b2c81dbc5637","ec2Type":"On Demand","":["3 days 0 hr","0"],"publicDNS":"ZZZ.us-west-2.compute.amazonaws.com","privateDNS":"172.19.106.55","nodeDescription":"hello","numExecutors":"1","labelString":"vdm.qa.auto-node-static","mode":"EXCLUSIVE","initScript":"#!/bin/sh\n#get public ip\npublic_ip=$(curl https://ipinfo.io/ip)\n#change hostname\nhost_name=a$(echo ${public_ip} | sed 's/\\.//g')\necho \"${host_name}.vdmdev.com\" > /etc/hostname\nhostname -F /etc/hostname\n#modify /etc/hosts\necho \"127.0.0.1 ${host_name}.vdmdev.com\" >> /etc/hosts\necho \"172.19.106.45 XXX\" >> /etc/hosts\nsudo yum -y install java-17-amazon-corretto\nunlink /etc/alternatives/java\nln -vs /usr/lib/jvm/java-1.8.0-amazon-corretto/bin/java /etc/alternatives/java","remoteFS":"/home/jenkins","remoteAdmin":"jenkins","stopOnTerminate":false,"idleTerminationMinutes":"60","tags":[\{"name":"jenkins_server_url","value":"https://XXX/"},\{"name":"Name","value":"VDM_QA_AUTO_NODE"},\{"name":"jenkins_slave_type","value":"demand_vdm.qa.auto-node-static"}],"usePrivateDnsName":false,"tenancy":"Default","amiType":{"rootCommandPrefix":"sudo","slaveCommandPrefix":"","slaveCommandSuffix":"","sshPort":"22","bootDelay":"","stapler-class":"hudson.plugins.ec2.UnixData","$class":"hudson.plugins.ec2.UnixData"},"maxTotalUses":"-1","nodeProperties":{"stapler-class-bag":"true"},"metadataSupported":{"metadataEndpointEnabled":true,"metadataTokensRequired":true,"metadataHopsLimit":"3"},"Submit":"","Jenkins-Crumb":"f254e1a74f30fe7089e4c82edbeb46d323353c106feddafe6b91a3fe48c36e5f"}
        at org.kohsuke.stapler.RequestImpl$TypePair.convertJSON(RequestImpl.java:845)
        at org.kohsuke.stapler.RequestImpl.bindJSON(RequestImpl.java:604)
        at org.kohsuke.stapler.RequestImpl.bindJSON(RequestImpl.java:599)
        at hudson.model.Descriptor.bindJSON(Descriptor.java:624)
        at hudson.model.Descriptor.newInstance(Descriptor.java:594)

Note also that we are able to update the description via groovy without issue. i.e. this sort of thing works fine:

def aSlave = hudson.model.Hudson.instance.getNode(nodename)
aSlave.setNodeDescription('hello');