Drop down menus not populating

Hi.

I am using the json editor online as an editor for chart properties.

I have some nested collection properties that have some drop down values.
I am populating the editor with a schema and properties as per the instructions/examples.

These are not displaying, instead they are a simple text editing box.

This worked perfectly in in version 6.4.1.
I tried in 9.2.0 and more recently upgrading to 9.5.8 and this is when i noticed the issue.

Any ideas?

Regards

Dave