The longer FE slur (→EE) could be the initial version, which seems to be evidenced by a deletion that can be seen in A in the place where the slur's ending at the beginning of bar 276 should be expected. It is not entirely certain whether it was a slur that was deleted, while the slur at the end of bar 275 in A does not suggest that it should be continued.
Compare the passage in the sources »
category imprint: Differences between sources; Corrections & alterations
issues: Corrections in A, Deletions in A
notation: Slurs
