Hi @c_hoppen. When you created / placed the PartsList initially, did you choose a drawing view to associate it with, or did you choose a file from the file browser directly? If you choose a view, you could try changing the ModelState that the source view is referencing, and see if that also effects the PartsList that is based on that view. But I am not sure if that connection is maintained after the creation of the PartsList, because there does not seem to be any exposed method or property of the PartsList for getting or setting a DrawingView directly. If that does not work, then you may just need to delete then create a new PartsList to replace it. In a quick test of a new drawing with a single sheet, and single view in it of an assembly with multiple ModelStates, and a PartsList based on that view...if I manually change which ModelState that view is set to, it shows a small interactive dialog letting me know about the change, and asking me if would like to update all PartsLists in this document to use one or the other ModelState instead. That could be seen as a connection between the view and the PartsList, but that one view in that situation was the only reference to the model document, so it's difficult to judge. Not sure how we could avoid, or react to that question if attempting to change the ModelState of the view by code though. It may simply not be shown, and use a default response, or it may throw an error, because we need to answer the question that there is no way to do by code. Not sure.

Edit: Here is the link to the blue link shown at the bottom of that dialog image above, just for reference:
https://help.autodesk.com/view/INVNTOR/2024/ENU/?guid=GUID-7070AD70-276B-42C7-A163-46B38B9C2465
Wesley Crihfield

(Not an Autodesk Employee)