While working onthe following problem was observed:
- Added a content type with a translatable field
- Mark the "menu parent" column as non translatable
- Added a new content with setting the menu parent to
""(aka. put it below
- Translate the content to the other language
- Expected behaviour: The translation can be used as expected. The original translation will be untouched.
- Actual behaviour: The original field item is dropped
Critical vs. Major
You probably don't run into that issue with core fields, even image or field item could be problematic here.
Fix the field synchronization part.