I would like to follow the advice to disable the deprecated JNLP2 protocol on our server, but it seems like the Windows slave service cannot connect with JNLP4.

I disabled and deleted the existing slave service on the Windows machine. Then I disabled JNLP2 on the Jenkins master, and connected the slave again via using Java WebStart and slave-agent.jnlp, as described here.

So far so good, the connection was established and the master log confirmed that it was with JNLP4. Then I set up the Windows service ("File" > "Install as Windows Service"), but then when it started the connection couldn't be established, the master log showed that connection attempts were only made with JNLP2, not JNLP4.

Would be great if that could be fixed so that everyone can disable JNLP2.