Text added in long text field is not kept on the English version of a multilingual wiki

Steps to reproduce on a fresh 13.4.3 instance:
1. Go to wiki administration and set the wiki as multilingual.
2. Add French to the supported languages
3. Change the default language to French
4. Create an App Within Minutes with a Long Text field and a Content field. The app was created while French is default.
5. Click on Modifier button and add in the Long Text field a simple text like "this is a test".

6. Change the wiki language to English and add a simple text like "testing this" and save.
Shown in this screen recording - content-not-kept-longtext-field-multilingual-wiki.mp4

Expected result:
The "testing this" text is saved and is displayed accordingly only on the English wiki.

Actual result:
The "testing this" text is not displayed accordingly on the English wiki, the initial text from the French wiki is shown.