@Alain_Hamel: Not really sure since it’s hard to replicate, but it could be that the level names in your files are just different. The families already inserted stay linked to the graph: they are not erased but rather created in a new location each time you re-run it. To duplicate elements, just use Family Instance By Point in Transaction from Bakery. Another tip that could lie in the thread you mention is to run the graph once, disconnect the Family Instance node, re-run (the objects will disappear from Revit), then undo in Revit (the objects will re-appear but disconnected from the graph, no blue point anymore). Then reconnect, change parameters and re-run.