Nothing indicates that the delayed start of slur In FE and GE could be authentic. The engravers or revisers possibly tried to avoid beginning a slur on a tied note. In case of GE, the inauthentic slur could have resulted from the inaccurate notation of GC wherein bar 120 starts a new line with a slur running from the first note, therefore as in GE. However, this does not justify omitting the clearly written opening fragment of the slur in bar 119.
Compare the passage in the sources »
category imprint: Differences between sources
issues: GE revisions, FE revisions
notation: Slurs