I have a multi-branch pipeline where I've replaced a boolean parameter with a choice parameter but the "build with parameters" page shows the old boolean parameter; this is after I've done a dummy run to pick up the change. The log reports that it read the pipeline from the latest commit on that branch (master) which has the parameter change.

In branches/master/config.xml, I see that the new parameter is listed in the parameters element, but the definition in parameterDefinitions is the old one! Here's an excerpt of that file - the old parameter is named REBOOT_FIRST and the new one is REBOOT_WHEN:

<flow-definition plugin="workflow-job@2.33">
  <actions>
...
<org.jenkinsci.plugins.pipeline.modeldefinition.actions.DeclarativeJobPropertyTrackerAction plugin="pipeline-model-definition@1.3.9">
...
      <parameters>
        <string>REBOOT_WHEN</string>
...
      </parameters>
...    </org.jenkinsci.plugins.pipeline.modeldefinition.actions.DeclarativeJobPropertyTrackerAction>
  </actions>
...
  <properties>
    <hudson.model.ParametersDefinitionProperty>
      <parameterDefinitions>
        <hudson.model.BooleanParameterDefinition>
          <name>REBOOT_FIRST</name>
          <description>...</description>
          <defaultValue>true</defaultValue>
        </hudson.model.BooleanParameterDefinition>
...

(I've elided various irrelevant bits with '...')

So it seems like the first list has been updated, but the actual definition hasn't. THis has left me with a broken pipeline that I can't recover without editing config.xml manually and restarting Jenkins; I haven't yet tried this but I expect it to work.

If updating any plugins would help, please advise and I'll try that, subject to my sysadmin approving.