Attachment not found when trying to use office import in wysiwyg editor

Reproduction steps:

• Start office server in administration
• Edit a document with WYSIWYG editor
• Click on "Import Office file" from the menus
• Select a file and click import

Expected result:

• the office file is properly imported

Obtained result:

• the WYSIWYG editor displays a "Office import failed" notification
• the console displays the following error:

  2022-05-03 14:13:44,916 [qtp1608297024-112 - http://localhost:8080/xwiki/bin/get/TEstTest/?sheet=CKEditor.OfficeImporter&language=en&fileName=ToSplit.odt&filterStyles=true&useOfficeViewer=false&outputSyntax=plain] WARN  w.s.WysiwygEditorScriptService - Failed to import office attachment [xwiki:TEstTest.WebHome@ToSplit.odt]. Root cause is: RuntimeException: Attachment not found: [xwiki:TEstTest.WebHome@ToSplit.odt].