Hi Phil,
Thanks for the question.

“Sky Keys” is a 4-Part Performance.
Acoustic Piano in Part 1 across all keys
Pad/Choir in Part 2 across all keys
Syn Comp in Part 3 across all keys
Synth Bass (Mono) in Part 4 mapped C1 to F#2 (only comes in when the Super Knob is advanced)

The synth bass has Portamento (what you are calling glissando) this can be turned on an off as follows

From the [HOME] screen
Press [PART SELECT 4]
Press [EDIT]
Touch “Part Settings” > “Pitch”
Turn Off the Portamento “Part Switch”
Store your newly edited version of the Performance
Thanks for the question.

Extra Credit: Alternate Methods
Each Part has its own Part Switch. In this Performance the bass is the only sound with the switch On
You also see the “Master Sw”
You can also set the “Time” = 0 to defeat it
Alternatively, you can switch the mode to “Fingered” — which would only apply it when you played legato.

Portamento Time is a programmable Parameter.
If you move the cursor to highlight “Time” and set the value to 0
Notice the [Control Assign] button is glowing
Press [Control Assign]
Press [AsgnSwitch 1]
You are taken to the Control Assign for this parameter
“Destination” = Portamento Time
“Source” = AsgnSw 1
“Curve Type“ = Standard
“Polarity” = Uni
Set the “Ratio“ to a positive value that represent how much (how long it will take to reach the next pitch)
Set to around +8

The AsgnSw is set to Latch (so when/if you want to bring in that Portamento you can turn On AsgnSw 1. This way you can recall the Performance without Portamento, but can bring it in when the Switch is pressed).

Thank you, Phil!