Midway Portamento Pitch Change Glitch

1. Notate two notes over an octave apart next to each other, first note must be the higher note (2 Octaves & on instruments that sustain notes {e.g. Violin} for clearest demonstration of glitch)
2. Add a glissando between the notes
3. Set glissando type to portamento in inspector
4. Playback

Expected Behaviour: Instrument should smoothly slide down from starting note to finishing note

Actual Behaviour: About halfway through the portamento's pitch jolts up to probably 8th, 9th or 10th octave (at an estimation).

Side Note: Octave or under portamentos don't do this but will play the starting note for a millisecond before playing the ending note.