I updated my Jenkins LTS installation from version 1.580.3 (LTS) to 1.596.1 (LTS). With both version I used/use the Job Generator plugin 1.22.

After the update I am facing the problem, that everytime I configure a Job Generator via the web interface, the Job Generator loses its "Custom Workspace" setting.

This bug is fully reproducible with 1.596.1:
Just create a Job Generator and configure a Custom Workspace for it. When you save the configuration, the config.xml has the correct element and value. When you configure it again, the value is not loaded into the configuration formular. When hitting "Save", the value disappears from the config.xml.

It is not reproducible with 1.580.3.

For me this is a real showstopper as I cannot edit my Job Generators without copying the value of "Custom Workspace" from the config.xml into the formular everytime (my whole project setup depends on it).
This bug may be related to https://issues.jenkins-ci.org/browse/JENKINS-23390.