My wiki is not multilingual, but I had it once set to multilingual to see how it works.
But the issue is related to this.
Page info:
Localization settings before:
After chainging to multilingual and English, it works. Change history as follows:
When I change back to single language, the modification is not visible anymore.
Where do I find the page XWiki.InplaceEditing? I did not work yet with the object editor.