The rhythmic notation of the majority of the sources is incorrect, since the group has only 8½ semiquavers. Therefore, it is most probably a mistake of the engraver who, presumably, added a beam almost "automatically" (in similar situations it is the figures in which the note after the rest is shorter than the previous that appear more frequently). Cf. a similar situation in bar 81. The mistake was revised in GE2 after A and arbitrarily in EE3 (the latter is still erroneous, since the group has, contrary to the indication, only 8 semiquavers).
Compare the passage in the sources»
category imprint: Differences between sources
issues: EE revisions, Errors in GE, GE revisions
notation: Rhythm