cf https://code.ametys.org/projects/AMETYS/repos/cms/browse/main/plugin-cms/resources/js/Ametys/plugins/cms/content/controller/ArchiveMenu.js#111
In Ametys.plugins.cms.content.controller.ArchiveMenu, if there is more than one content with scheduled archiving, the method _addMultipleSchedulingDescription is called but does not exists.
Suggested fix : always use the standard case ( description = this._handlingMultiple(description, 'scheduled-archiving', scheduleArchiveContents); )
Here is a screenshot when using the standard case :
