I'm using SigmaStudio 4.6 and have noticed a consistent issue that occurs when dragging and dropping nodes from the ToolBox onto the schematic. After dropping the new node onto my schematic, if I click anywhere before waiting 3-5 seconds, it creates another instance of the dropped node. Repeated clicking creates additional duplicate instances.
While this can be easily worked around by simply waiting several seconds after dropping each new node, it does make rapid prototyping more error-prone and difficult. I find myself often dropping a new node and immediately going to drag a connection off of it, which ends up creating several new instances of the dropped node.
This behavior happens for every node type, and happens consistently.