You can STORE a Volume Offset for a Performance in a Live Set, it applies when you recall the Performance via that particular Live Set slot. If the same Performance appears in the Live Set multiple times — each could be stored with a different Volume setting. As you might need to be louder or softer depending on what else is going on onstage. You might need to be 127 during your solo, and 98 during the vocals.

I find if we use specifics it makes it easier to fill in the missing pieces. Say in a Live Set you have the following entries:

My CFX Concert (112)
Seattle Sections (117)
My CFX Concert (125)
PopHorns Dyn Shake (114)
My CFX Concert (127)
The Basics (107)
My CFX Concert (98)
FM PWM Pad (111)
Seattle Sections (79)

You are using a Yamaha FC5 Foot Switch to advance through your Live Set listings... shown above, each of these in a Live Set slot with the Volume Offset in parenthesis. The Performance “My CFX Concert” is my edited version of the factory sound.

When you recall the “My CFX Concert” in Live Set slot 1 it will be recalled at a volume of 112
When you recall the “My CFX Concert” in Live Set slot 3 it will be recalled at a volume of 125
When you recall the “My CFX Concert” in Live Set slot 5 it will be recalled at a volume of 127
When you recall the “My CFX Concert” in Live Set slot 7 it will be recalled at a volume of 98

But if you recall the original “My CFX Concert”, not through a Live Set, it will be set at the original Volume of 66.

The Live Set points to the same “My CFX Concert” each time, but Offsets the volume each time it is recalled within the particular LIVE SET slot. If you exit the Live Set completely and recall the original source “My CFX Concert” - it still is unchanged from its original stored Volume.

Summary: the Live Set can store a different volume (offset) for a Performance for each different slot you place it in.
If you are thinking each is completely unique, STOP. They are all the same except for the Volume Offset, the Color scheme you can select, and the little bit of text (Slot Name) you can write underneath the Performance Name which get associated with the data slot.

What's happening here makes sense to me. And I can understand why you'd be puzzled. There's a "silent partner" or "ghost in the machine" for you to discover here.

Each Live Set slot can point to a Performance. Along with "just" pointing to a Performance, each Live Set slot has its own volume associated with the slot.

(aside) Personally, I think it would have been "better" for Live Set to have, along with the 128 possible volume values (0-127) to have a value "Perf. Vol" which did not override the Performance's volume and, instead, would just use whatever volume the Performance had saved - even if you end up changing the volume as you have.

... the Live Set slot's volume will override the Performance's programmed volume value unless the Live Set happens to match the Performance's programmed volume level. When you first add a new Live Set slot entry which points to a Performance, the Live Set will "fill in" to the Live Set's volume (which is this "override" value) the current value of the Performance's volume.

When you go and change the Performance's volume - this does not change the Live Set's volume override value. So if you do change the Perf's volume, then using the Live Set to recall this same Performance will use the "old" override value which is what you saw.

If you're only going to be recalling this Performance using Live Set - then you don't really have to edit the Performance volume at all. You can elect to only edit the Live Set override volume. Go to Live Set, select the Performance you're interested in, press the "Edit" button or tap the "Edit" touchscreen button. You'll see the volume at the bottom. You can change this to a new value and save/update the Liveset slot entry. Not through [STORE] (which is a Performance feature) - but through "Done".

If you want both the Live Set and Performance to match after this update - you can either edit the Performance first then create a new entry based off the updated Performance (as you've done already) - or you can manually edit the Live Set as outlined in the last paragraph and then go back and also manually edit the Performance itself.

Many thanks for replies.
Understood.

Max