The entire score is at IMSLP (5.46 MB pdf)
The issues seem to relate to the 2nd movement which wanders between 2/4 and 6/8 without TimeSig changes. It is fairly common for pieces of this difficulty to omit them. I don't see any rhythmic oddities.
I suspect the "5 beat" measure is at the top of page 25. I would render it as:
!NoteWorthyComposerClip(2.0,Single)
|Clef|Type:Treble
|Key|Signature:Bb,Eb,Ab,Db,Gb
|TimeSig|Signature:2/4
|Note|Dur:8th|Pos:8|Opts:Stem=Down,Beam=First
|Note|Dur:8th|Pos:5|Opts:Stem=Down,Beam=End
|Note|Dur:8th,Triplet=First|Pos:4|Opts:Stem=Down,Beam=First
|Note|Dur:8th,Triplet|Pos:5|Opts:Stem=Down,Beam
|Note|Dur:8th,Triplet=End|Pos:3|Opts:Stem=Down,Beam=End
|Bar
!NoteWorthyComposerClip-End