IFR RNAV approaches

Hello, very happy to be part of this excellent initiative!!
Happy with my EC135 v.5.33a
I have a question, but not sure if this is the right place for it (not a German speaker)

Question:
Why I cannot run an RNAV approach on the AP of the helo (only manual approaches)... the GPS/VLOC switch goes back to ILS when I push the APP and GS buttons on the AP if I want to select an RNAV (GPS) approach
Am I doing something wrong?

Your observation is completely correct. The EC 135's autopilot does not support GPS approaches - also in reality.
To follow an ILS, the appropriate frequency must be set.