Bug in SceneBuilder 9

[Sverre Moe]

I think I have found a bug in SceneBuilder 9.

I cannot find an existing bug report for this:
https://www.oracle.com/search/results/_/N-8d?Ntt=SceneBuilder%20TitledPane&Dy=1&Nty=1&cat=bugs&Nr=106&Ntk=S3

When adding a TitledPane, its default styling is not applied.
Within SceneBuilder the TitledPane lacks the border and title
styles(background, collapsible arrow). An empty TitledPane shows only
the title and nothing more. It looks just like a Label or Text.
Running the FXML with an Java 9 application shows the TitledPane as it
should be.

Where should I submit this bug report?
bugreport.java.com, GitHub mirror or with Gluon?

/Sverre