That’s down to the note (or synth) having decayed away … it’s also important to audition a useful parameter if exploring
A simple test case is a dvco with the initial voice configuration (two identical low harmonic waves) - set those to decay infinitely (and ensure the amp or filter env is not truncating the drone)
Now when you set a solitary modulation of +48 to destination Osc2Detune you get a range of on octave across the whole velocity range
if you tap the track pad now (with velocity to Vol set to OFF in sound settings - and not using the FIXed pad velocity button) you will see(and hear) the relationship between the input velocity and the detune offset
As you know gauging the velocity input is tricky, however, because we have a droning note (and a parameter which is audible) you can now use the level encoder to audition the velocity range in-situ
The important thing you want to establish is now simpler for you to fine-tune
Velocity of 100 is not a relative position in terms of the bipolarity of the modulation
You need to think of velocity being monopolar like a Modwheel, not like a pitchbend wheel (and certainly don’t get distracted by the velocity you generally program)
The modulation depth is bipolar, but the source is not
Therefore a velocity swing of +/-10 around 100 will strengthen or weaken relative to 100, but it won’t show bipolarity for most situations (i.e. you could have an offset on pan as the current track setting and the range +/-10 around 100 may shift the pan left/right of centre, but it is NOT to do with the velocity you strike being 100, that’s arbitrary)
So, there’s no midpoint velocity, in the terms you ask about.
You cannot hit with velocity 0 btw - this is where the menu can be a little misleading (you can dial the velocity back to zero with the level knob, but you can never strike or program a Midi Note on with a velocity < 1)
In this regard, a velocity modulation macro (with a non-zero depth) will always have an effect potential on the sound
You can fine-tune your vel-mod macros relative to a programmed velocity of 100 by fine tuning the depths in the macro menu, but this is akin to parking your modulation wheel at 100 and tuning depths relative to that
Velocity is a useful source for things like dynamics, but it’s a bit harder than other mod sources to utilise in a deliberately controlled way, especially as it’s so hard to play consistently and is generally tied to volume too
The other way you can audition the effect is to preprogram a sequence with velocity steps to taste, or set a 1st condition to drone a note … but for some parameters you will obviously need to retrigger the note (therefore trying to adjust the faux-velocity level encoder in real time will be meaningless, unless it’s a sustaining parameter, like pitch)
I think adjusting your title from [Rytm Velocity Mod level not working] to [Rytm Velocity Mod level configuration ?] would be helpful