Newly created subfolders will not be displayed in the navigation/folder panel unless you perform a complete restart of Bridge. Since the required little subfolder ticks on the side are missing, it is not possible to access or drag and drop anything into the new subfolder without a restart.

The manual refresh button doesn't help either as it will only affect the image content panel, not the file structure/navigation itself. The best would be to automatically refresh both automatically without having to look for an extra button.