The version of GE1 is certainly a mistake of the engraver, corrected in GE2. The bottom note of this dyad is devoid of natural in GC, FE and GE1, which in all of the cases is a patent error.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: EE revisions, Errors in GE, Terzverschreibung error, GE revisions
notation: Pitch