FE features an A1 as the minim on the 2nd beat of the bar. If we take into consideration the piano part and this bar only, the note would be absolutely natural, yet in a broader context, it is obviously erroneous, since the stability of the bass note is out of the question in this place – cf. C-c in the double basses and cellos in Morch. The mistake was corrected in EE, most probably following the logic of the harmonic progression. Chopin did not notice this mistake both in the proofreading of FE (in spite of adding an accent!) and during lessons, which may mean that the pupil did not notice it either.
Compare the passage in the sources»
category imprint: Interpretations within context; Differences between sources
issues: EE revisions, Errors in FE, Terzverschreibung error
notation: Pitch