When I use the jclouds plugin to spawn instances at DigitalOcean and EC2, I noticed that the single-use slaves are never removed. They are marked offline as soon as the job finishes, but they remain offline in Jenkins and they are active with the cloud provider.

As soon as the job finishes, I see this in the logs:

 2020-04-02 18:30:42.634+0000 [id=3070]	WARNING	j.p.j.c.JCloudsOneOffSlave$JCloudsOneOffSlaveDisposer#tearDown: Taking single-use slave [COMPUTER_NAME] offline.

I let it sit for two hours and nothing changed. I had to delete the agent manually from inside Jenkins' build executors listing.

Am I missing a step? I'll gladly turn on more debug logging if that would help diagnose the issue.