Thanks for your reply Nicolai and you were right. The issue was the side I configured my modules. Took some time to realize

I received a set consisting of a RevPi Core S, 2 MIO modules, and a DIO about three weeks ago. Initially, I used PiCtory to arrange the
hardware topology (see 2nd attachment) and started working with the revpimodio2 Python library. I was able to read and write values to all IO modules successfully ...