CTRL+Z: undo works, but looses the TrackChange-INS

problem:

• open a segment with empty content (with TrackChange-Plugin on)
• use CRTL+. to copy content from source; content is marked correctly as TrackChange-INS
• delete a character from within the new content
• use CTRL+Z to undo the deletion => deletion is undone, but the content is not marked as TrackChange-INS any longer