Since:
I assume it lasts for at least 3 weeks.
Until a recent update (didn't receive the detail from our dev team about the bug right after the update so not sure to which it applies)
I also downgrade to 2.13 with no luck

When:
Both upon job creation and job modification

How to reproduce:
Create a Maven job and fill the fields "Root POM" and "Goals and Options" in Build with random (but valid ...) values
The matching values in the config.xml are not created

How to counterpass this:
Edit the config.xml file via SSH and restart Jenkins so it re-parse the file