Notch and Resolume - OSC

I have no idea if this is a Resolume or a Notch thing so asking on both forums.

I have set up OSC from Resolume into Notch and works fine at first - whether I control the Resolume slider manually or set it to one of the automated animation settings like BPM.

However, when I add an envelope to it, nothing changes. I can see in Resolume the numeric value changes in respect to the envelope, but in Notch, it continues to be a linear ramp from 0 to 1.

Is this an OSC limitation from Resolume perhaps that someone else here has encountered? Or has anyone got the above to work?? In which case I’ve set something up wrong.