The curved line written in A between the voices is at the pitch of b
1 and almost certainly indicates that the dotted crotchet at this pitch should be sustained, as clearly marked by Chopin in AsI (both in the piano part and in the clarinet II part). In GE1 (→GE2) the endings of the tie are placed lower and not horizontally, which makes the tie seem to concern 4 quavers in the bottom voice. This is how it was reproduced in FE and FESB (as a slur), whereas in EE and GE3 it is undoubtedly a tie to b1.
Compare the passage in the sources »
category imprint: Graphic ambiguousness; Differences between sources
issues: Inaccurate slurs in A
notation: Rhythm