In the app there are settings for short press and long press, but my jawbone only does stuff when I long press it. This is fine for going to bed. Using it as a simple trigger throughout the day would be cool too.
I believe the short press doesn’t actually trigger the Up24 to communicate with the phone and register some kind of send/receive which is what is needed. I believe I came to the same conclusion when I initially set it up in the same app as you. Not sure if multiple short press could trigger something. I never use it, but I think stop watch start is two shorts and a long press etc.