Issue

Changes made to a slave’s configuration are not persisted in its config.xml

Environment

CloudBees Jenkins Enterprise

Resolution

You will need to manually edit the slave’s config.xml file to remove the
temporary offline lines:

<temporaryOfflineCause class="hudson.slaves.OfflineCause$UserCause">
<description>
<holder>
<owner>hudson.slaves.Messages</owner>
</holder><key>SlaveComputer.DisconnectedBy
</key>
<args>
<string>anonymous</string>
<string/>
</args>
</description>
</temporaryOfflineCause>