Steps to reproduce:
1. Create a class, a sheet and a template
2. Edit the sheet and provide a custom display, any custom display
3. Set the wiki to multilanguage and define some languages, EN and FR for example. EN is the default wiki language
4. Create a document instance with the newly created class.
5. Edit the document in the default language, which for example is EN
6. Edit the document in its translated language, FR for example
7. It bypasses the sheet and goes to WYSIWYG editor. View mode uses the sheet though for both languages.