How to control a Max4Live parameter from a Max patch?

On an Ableton audio track I have a Max4Live device which controls the global transposition of all the session samples. The device code can be found below, that you can put into a Max4live patch.

I'm trying to control the number box (which changes the transposition) in the Max4Live device, from a Max patch in a separate window.

Using the UDPSend/Receive objects doesn't entirely work. Here is how I'm using the UDPSend/Receive: https://imgur.com/a/DxIn8
The problem: When I scroll through the numbers in the separate max patch, the numbers scroll through on the Max4Live device, but the pitch doesn't change and the arrow in the number box stays gray. I can see this is because the number box needs to be 'selected' (i.e. the arrow in the box needs to be orange). I have tried adding a live.dial instead of a number box and midi mapping this, but the same thing happens.

Any help would be greatly appreciated!