Jenkins 2.61 (and at least as far back as 2.58) with the Matrix Project plugin 1.11 (and 1.10) are not  (always) running on their assigned node.

I have a job that pushes backups into the cloud from a specific node, so it is important that the job runs on that node. The job has a user-defined axis which specifies the source directory, so that it can run multiple types of backup.

When I run the job, the touchstone build runs on the assigned node and the job with the second axis value runs on the assigned node, but the job with the first axis value runs on a different node.

As I changes the axis values, the job starts to run on different incorrect nodes.

This appears to only happen on matrix jobs, not others. I'm not sure how long this has been happening for, as we don't otherwise have many matrix jobs that should run on one specific node only.

I'm not sure if it's relevant, but when I configure the matrix jobs in question, the advanced section with the "Restrict where this project can be run" option is collapsed, as if it contains no configuration.