Has anyone got the sticky toolbar working in Umbraco 12 for the TinyMCE editor? According to the tinymce docs, set toolbar_sticky to true, but it doesn't appear to have any effect. So if I have a long chunk of text in the editor and scroll down, the toolbar still disappears off the top of the screen.

So my appsettings.json contains the following within Umbraco.Cms.RichTextEditor:

"CustomConfig": {
  "entity_encoding": "raw",
  "toolbar_sticky": "true"
}