A separate slur over bar 52 is certainly a mistake by the engraver of EE who started one-bar-long slurs a bar too early. The ending of slur in bar 52 (at the end of line) is inaccurate in FE – it suggests a continuation not to be confirmed by the slur in the next bar.
Compare the passage in the sources »
category imprint: Graphic ambiguousness; Differences between sources
issues: Inaccuracies in FE, Errors in EE, Uncertain slur continuation
notation: Slurs