As in bars 35-36, the tie sustaining F is most probably an erroneous interpretation of the motivic slur of e-f added by Chopin in the proofreading of FE1.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: EE revisions, Placement of markings, GE revisions, Authentic corrections of FE, FE revisions
notation: Slurs