Ecodim 4 group switch long down issue

I recently bought an Ecodim 4 group wireless switch. Using an Advanced Flow, I want to initiate an action when I do a long press down (dim). I works fine for long press up, but long press down does not work. It works fine for a 2 group wireless switch.

Anyone has the same issue or has the same switch an can do a quick test? I do not know if it is an issue with the switch itself or the Homey Ecodim App. I tried to send a mail to the developer, but that mail address is not valid.