This is basically a request to add https://www.drupal.org/project/admin_menu_source into Backdrop core:

This would be a nice solution for what this person is trying to achieve in https://forum.backdropcms.org/forum/flyout-menu (aside from the vertical placement of the admin bar).
This is one of the things I'm planning to discuss during the Content Author-centric UX improvements in core session in the upcoming Backdrop Live event.
Recent comments
@yorkshirepudding, In the end I fixed it by deleting the config/active folder contents, copying the config/staging/ files into config/active, importing the database again and clearing the caches...
Importing the staged config throws an error: another field with the same name already exists
Thanks, I have to go out now, I will try later on and report back
Importing the staged config throws an error: another field with the same name already exists
Hi Francis. Yes, what config do you have in staging for it? You might have configs like: field.field.field_video_embed field.instance.node.page....
Importing the staged config throws an error: another field with the same name already exists