The octave in A is the original version, changed by Chopin in a proofreading of FE (→GE,EE). In FE the correction was inaccurately performed – there are no dots extending the added notes, while the 
(cautionary) was placed at the pitch of b2. The rhythmic error was corrected in GE and EE and the was moved before a2 in GE1, yet removed in EE and subsequent GE,s.
Compare the passage in the sources »
category imprint: Differences between sources; Corrections & alterations
issues: EE revisions, Errors in FE, GE revisions, Cautionary accidentals, Rhythmic errors, Authentic corrections of FE
notation: Pitch