What am i doing wrong?
It looks like you are using one of the newer offline-enabled Workforce projects. This has a different information model compared to the older classic projects and requires you to upgrade to version 1.8.3 of the ArcGIS API for Python. A pre-release version of 1.8.3 has been made available (that contains everything you need to work with old and new Workforce projects). You can install the pre-release version from Anaconda using:
conda install -c esri/label/prerelease -c esri arcgis
Oh great! Thanks