Not all notes are being exported

Not all notes are being exported

In order to make copies of my content for safety reasons, I exported certain notebooks. But now, not even half of the content is being exported. Why not? If I cannot save or auto-save everything, I definetly need another app since I work a lot with notes.

And also, I can only export on my WIndows laptop, not on my iPad or Android Smartphone. Makes me really worried about my content. Is that a really huge bug or intentionally?