@tweedledope The static setup code can typically only be used once after each factory reset. You can generate a new temporary one by pressing "share device" or similar in the Matter controller that the device has already been added to.
Also, out of curiosity, what is the storage capacity on the Flic Hub LR? I have a database that is logging Matter connection/disconnection events and curious if/when it would get too large and mess things up.
And this is the code I'm using in FlicHub studio to handle the matter events for volume-up, volume-down, volume-set, toggle operations and preset handling.
Unfortunately I was not able to reproduce this, to make sure I understand you correctly, this is how I add the virtual device and assign it to my Twist.