Custom properties are not scaffolded and all generated layout have title and description only

After creating a custom document type, the user generates the corresponding layouts and:

• Create, edit, import and metadata layout only contains title and description
• There is no more layout inheritance

Same happens if the parent type is File, Folder or any other document type.

It worked for sure until  the 18th of September 2020 as I gave a Studio Training at that moment and the trainee hadn't faced this problem