Change the DPT from 20.015 to 5.005! It will work, I have many ME AC Intesisbox Interfaces and they all work fine.
Try your setup in things like this:
Type number : Kanal_22_B "Klimaanlage Büro Modus [%s]" [ ga="5.005:2/6/1+<2/6/1" ]
Something that might not be working with this interface is that it has a control and a status object which you should pair in different ga’s (2/6/1+ a new one for status): object 1 for control and object 47 (or 44 depending on parameter configuration) for status.