[Bug] Writing filter settings to MIDI device does not work

[gbdlin]

Problem

Writing value based on filter setting change does not work

Steps to reproduce

1. Set up any filter containing settings for any source
2. Create a binding listening on any value of this filter and writing it to the MIDI device (pick midi attribute you can observe)
3. Go back to filter settings and try to change the value to trigger the MIDI write
4. Observe the result

Expected result

MIDI device state should change

Actual result

Nothing happens

Example

I have an audio source (called audio_mikser below) with simple gain filter. I've set up binding for it as follows:

When I change the gain value manually in OBS, control value on my midi device does not change.

[lmerkens]

can't get it to work either...