Hello Fabian,
Thanks for the clear description
The behaviour you describe is not what we would normally expect. Since the OSC task works from its individual Execute button, the B-Station2 is able to communicate with the LPU-2.
Could you try a fresh Action with only this task:
OSC → Send Bool → Set
URI: /pb09/go+
Value: true
Then open Monitor → OSC and compare what happens when you execute the task individually, execute the complete Action, and trigger the Action from a button.
For this test, please use /pb09/go+ rather than /pb09/bu, since /bu requires a true → false sequence to emulate the Cuety button press.
You can also try the built-in
Buttons -> LPU-2 template as a comparison.
If the OSC message appears in the monitor when executing the task individually, but nothing is sent when executing the complete Action, please send us a screenshot of the Action and OSC task configuration, your Settings → OSC page, and if possible a backup of the B-Station2 configuration and the LPU-2 firmware version. We can then reproduce this here on firmware 1.24 and investigate further.
Hope this helps!