CoreInk Multifunction Button not working

[hooble]

Hi all

I am facing a weird problem with a new CoreInk -> the multifunction button does not work. I am using UIFlow 1.12.4 and created the following Blockly:

But pressing the button UP simply does nothing. If I swap UP to EXT and press the EXT button, the image gets changed and I hear a beep.

Am I doing something wrong here?

Thanks a lot